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Chapter 9 • Confusion in Older Adults
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109
DIFFERENTIAL DIAGNOSIS OF
Common Causes of Delirium, Confusion, Dementia,
and Depression—cont’d
CONDITION HISTORY PHYSICAL FINDINGS DIAGNOSTIC STUDIES
Depression Onset of confusion often abrupt, with
some diurnal variation, generally more
consistent over time than delirium;
confusion of short duration compared
to dementia; past history of psychiatric
problems common, including undiagnosed depressive episodes; cognitive
losses fluctuating rather than stable
over time; sleep/appetite disturbance;
hallucinations usually absent although
person can have suicidal thoughts
ABGs, Arterial blood gases; BUN, blood urea nitrogen; CBC, complete blood count; CT, computed tomography; CVA, costovertebral angle; DTRs,
deep tendon reflexes; ECG, electrocardiography; EEG, electroencephalography; LFTs, liver function tests; LOC, level of consciousness; MRI,
magnetic resonance imaging; PET, positron emission tomography; TFTs, thyroid function tests; U/A, urinalysis.
References and Readings
Adelman AM, Daly MP: Initial evaluation of the patient with sus-
pected dementia, Am Fam Physician 71:745, 2005.
American Psychiatric Association: Diagnostic and statistical man-
ual of mental disorders, ed. 5, Arlington, Va, 2013, American
Psychiatric Association.
Burns A, Iliffe S: Dementia, BMJ 338:405, 2009.
Cotter VT: Alzheimer’s disease: Issues and challenges in primary
care, Nursing Clin North Am 41:89, 2006.
Galvin JE, Roe CM, Powlishta KK, et al: The AD8: A brief infor-
mant interview to detect dementia, Neurology 65:559, 2005.
Gleason OC: Delirium, Am Fam Physician 67:1027, 2003.
Inouye SK, VanDyck CH, Alessi CA, et al: Clarifying confusion:
The confusion assessment method. A new method for detecting
delirium, Ann Intern Med 113:941, 1990.
Kuslansky G, Buschke H, Katz M, et al: Screening for Alzheimer’s
Disease: The memory impairment screen versus the conventional
three-word memory test, J Am Geriatr Soc 50:1532, 2002.
McCusker J, Cole MG, Dendukuri N, Belzile E: The Delirium
Index: A measure of the severity of delirium: New ndings on
Depressed or anxious mood; tends
to highlight disabilities, especially memory loss; memory loss
equal for recent and remote
events; physical examination
often normal
reliability, validity, and responsiveness, J Am Geriatr Soc
52:1744, 2004.
Milisen K, Braes T, Fick DM, Foreman MD: Cognitive assessment
and differentiating the 3 Ds (dementia, depression, delirium),
Nurs Clin North Am 41:1, 2006.
Sendelbach S, Guthrie PF: Evidence-based practice guideline: acute
confusion/delirium. Iowa City, Iowa: University of Iowa Gerontological Nursing Interventions Research Center, Research Translation and Dissemination Core. 2009 Mar. 66 p. National Guideline
Clearinghouse 7:14340, Dec 2009. Retrieved from http://www.
guideline.gov/content.aspx?id514340&search5confusion.
Snyderman D, Rovner B: Mental status exam in primary care: A re-
view, Am Fam Physician 80:809, 2009.
Thibault JM, Steiner RW: Efcient identication of adults with de-
pression and dementia, Am Fam Physician 70:1101, 2004.
Wei LA, Fearing MA, Sternberg EJ, Inouye SK: The Confusion As-
sessment Method: A systematic review of current usage, J Am
Geriatr Soc 56:823, 2008.
Young J, Inouye SK: Delirium in older people, BMJ 334:842, 2007.
Geriatric Depression Scale
in elderly; CBC, electrolytes, glucose, BUN,
creatinine, LFTs, TFTs,
serum B12, folate,
serology for syphilis,
ABGs, toxicology
screen, blood alcohol
level, U/A, ECG, EEG,
chest radiograph, lumbar puncture, CT or
MRI (when CVA or
injury suspected)
CHAPTER
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10
onstipation is a common symptom and is a sub-
C
jective interpretation of a disturbance of bowel
function. There is lack of general agreement on the
norms for stool frequency, size, or consistency, with
considerable uncertainty on how much deviation is
required to warrant the label of constipation. Generally, constipation refers to a failure to completely
evacuate the lower colon. This is associated with difculty in defecating, infrequent bowel movements,
straining, abdominal pain, and pain on defecating. It
can also refer to hardness of stool or a feeling of
incomplete evacuation. Obstipation refers to intractable constipation or the regular passage of hard stools
at 3- to 5-day intervals.
There are ve areas in the defecation process where
interference can cause a disturbance in motility
and lead to clinical problems: (1) the peristaltic reex,
(2) the spinal arc, (3) relaxation of the anal sphincter,
(4) contraction of the voluntary muscle associated with
defecation, and (5) the autonomic and cortical control
of defecation. Both functional and organic disturbances can cause constipation.
Acute constipation refers to a sudden change for
that individual. This suggests an organic cause, such as
mechanical obstruction, adynamic ileus, or traumatic
interruption of the nervous system from medications or
following anesthesia. Persistent constipation occurs
when the condition lasts for weeks or occurs intermittently with increasing frequency or severity. Partial
obstruction or local anorectal conditions could be the
cause.
Chronic constipation occurs as the result of disruption of the storage, transport, and evacuation mechanisms of the colon. Functional causes are the most
common and include poor bowel habits; inadequate
intake of dietary ber, bulk, and uids; and anal ssure
pain. Genetic predisposition to constipation seems to
exist.
Constipation
DIAGNOSTIC REASONING: FOCUSED
HISTORY
Is this really constipation?
Key Questions
l
How many stools are there per day?
l
What is the consistency of the stool?
Frequency of Stool
Stool frequency is the easiest parameter to quantify. In
the general adult population, the “normal” frequency
of bowel movements ranges from 3 to 12 per week.
Having fewer than three bowel movements per week is
considered constipation.
Infants and children have decreasing stool frequency
with age, from more than 4 stools per day during the
rst week of life to 1.2 per day at age 4. Infants who
have a fewer number of stools than average are at
greater risk of developing constipation.
Alternating episodes of constipation and diarrhea are
characteristic of irritable bowel syndrome (IBS). Patients
describe their constipation stools as hard, round balls.
Stool Consistency
Dry, hard stools suggest a lack of sufcient dietary uids or ber. Stools that are marginally frequent but are
soft and moist do not indicate constipation. The same
number of stools that are hard and dry would indicate
constipation. Liquid stool and fecal incontinence, particularly in children and the elderly, can represent stool
impaction and overow.
What red ags do I need to consider?
Key Questions
l
Is there any rectal bleeding or blood in the stool?
l
Have you had an unintentional weight loss of more
than 10 lb?
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Have you had inammatory bowel disease (IBD)?
l
Have you or your family members had colorectal
cancer?
Bleeding
Black stools can indicate bleeding from a site in the
upper gastrointestinal (GI) tract. Bright red blood indicates bleeding from the lower GI tract and may indicate
a mass. Hemorrhoids and anal/rectal ssures can also
produce bleeding. Brisk bleeding is uncommon with
hemorrhoids and requires immediate investigation.
Unintentional Weight Loss
In an adult, an unintended weight loss of more than 5%
of usual body weight over a 6- to 12-month period may
signal an underlying cancer (see Chapter 39).
History of Inflammatory Bowel Disease
(IBD)/Colorectal Cancer
The patient with a history of inammatory bowel disease (Crohn disease or ulcerative colitis) or with a
personal or family history of colorectal cancer is at
increased risk for colorectal cancer. A change in bowel
habits can signal an intestinal tumor.
Is the constipation acute or chronic?
Key Questions
l
When did the constipation start?
l
How long have you been constipated?
l
Is this an individual episode or is it chronic?
l
At what age did the constipation rst begin?
Onset and Duration
Recent onset usually reects changes in lifestyle or
physical health such as dietary changes, activity
changes, new medications, partially obstructing lesions, or recent illness. Chronic constipation or constipation of long duration (more than 3 weeks) is
usually associated either with functional causes, such
as lack of dietary ber and bulk, or with concurrent
systemic disorders such as diabetes mellitus (DM) or
hypothyroidism.
Age of Onset
New-onset constipation in adults older than age 40 is
suspicious for colon lesions. Constipation in the newborn is likely to have an anatomical cause. In infants,
the cause is likely inadequate uid and ber in the diet.
In children, the cause is likely to be diet as well as
Chapter 10 • Constipation
111
developmental and psychological factors. In adults, the
cause is usually related to dietary and bowel habits.
If the constipation is acute, what conditions
should I consider?
Key Questions
l
Have you been ill recently?
l
Have you had a fever?
l
Do you have any chronic health problems?
Recent Illness
Dehydration and fever cause hardening of the stools by
diminishing intestinal secretions and increasing water
absorption from the colon. A transient period of consti-
pation is common during an acute febrile illness. Reex
ileus is sometimes seen with pneumonia.
Chronic Illness
Hardened stools are found in patients with renal acidosis
and diabetes insipidus. Infants and children with hypo-
tonia of the abdominal and intestinal musculature from
neurological conditions are predisposed to constipation.
Neurological gut dysfunction, myopathies, endocrine disorders, and electrolyte abnormalities can cause
constipation. Constipation in infants can be an early
symptom of congenital hypothyroidism.
If the constipation is chronic or recurrent,
what should I consider?
Key Questions
l
What do you usually eat in a day?
l
How many glasses of liquid do you drink each day?
l
Do you eat breakfast?
l
What are your usual bowel habits?
l
How active are you?
l
What medications are you taking?
l
Do you use laxatives? How often do you take laxa-
tives? How long have you used laxatives?
Dietary Pattern
A 3-day dietary history is more accurate than a 24-hour
recall, although a 24-hour recall can provide a reasonable picture of the patient’s dietary habits. Diets that
lack roughage result in lack of fecal bulk, causing an
inadequate stimulus for peristaltic movement. Diets
high in protein result in complete digestion of the
protein, leaving little residue to stimulate movement.
Diets high in calcium content lead to the formation of
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Chapter 10 • Constipation
calcium caseinate in the stools which does not stimulate peristalsis. Teenagers often drink several quarts of
milk per day, causing constipation. Inadequate uid
intake (less than six 8-ounce glasses per day) contributes to dry, hard, and infrequent stools.
Breakfast
Colonic motility is greatest following breakfast. Skipping this meal decreases the postprandial effect associated with food intake.
Bowel Habits
Postponing a bowel movement because of time constraints or other reasons suppresses the normal gastrocolic
reex and can produce constipation.
Activity Level
Constipation is a common problem in individuals with
a sedentary lifestyle. The lack of physical activity reduces the peristaltic reex. Overactivity can also cause
constipation as a result of the lack of adequate uid
replacement.
Medications
Medications that commonly cause or contribute to constipation include narcotics, imipramine, diuretics, calcium channel blockers, anticholinergics, psychotropic
agents, antacids, decongestants, anticonvulsants, iron,
bismuth, and lead.
stools a function of the size of the colon. Ribbon like
stools suggest a motility disorder, such as IBS. They can
also be caused by narrowing of the distal or sigmoid
colon from an organic lesion. A progressive decrease in
the caliber of stool suggests an organic lesion. Stools
with a toothpastelike caliber suggest fecal impaction.
Consistency of Stool/Fecal Incontinence
Dry, hard stools suggest a lack of sufcient dietary
uids or ber. Liquid stool and fecal incontinence,
particularly in the elderly, can represent stool impaction and overow. Overow incontinence in children
can indicate constipation from a fecal impaction.
Alternating Constipation and Diarrhea
Alternating episodes are characteristic of IBS. Patients
often describe the stool during the constipation episodes as hard and pellet-like.
What else do I need to consider?
Key Questions
l
Do you have the urge to defecate?
l
Do you have any urinary tract symptoms?
l
Do you have any nausea or vomiting?
l
Is there any pain with defecation?
l
Is there any bleeding with defecation? How much?
l
What color are your stools? Are the stools very dark
colored or black?
Use of Enemas, Laxatives, and Suppositories
Use of stimulants to empty the colon removes the
peristalsis stimulus for 2 to 3 days. Diarrhea is usually followed by infrequent stools for several days.
Chronic use of stimulants can produce chronic atonic
constipation.
How can I further narrow the causes?
Key Questions
l
Is the stool size large or small?
l
What is the general shape of the stool (e.g., small,
round, ribbonlike)?
l
Is the stool formed or liquid?
l
Have you had any involuntary loss of stool?
l
Does the constipation alternate with periods of diarrhea?
Size or Caliber of Stool
Infrequent passage of small, hard stools can indicate
congenital aganglionic megacolon. Very large stools
can indicate functional constipation, with the size of the
Urge to Defecate
Children with Hirschsprung disease (aganglionic megacolon) do not have an urge to defecate because the stool
accumulates proximal to the lower portion of the rectum
where the proprioceptors for defecation are located.
Evidence of stiffening, squeezing, and crying indicates
stool is being propelled to the rectum. Adults who overuse laxatives or other stimulants also cannot experience
the urge to defecate.
Associated Urinary Tract Problems
Voiding problems can indicate an abdominal mass.
Day and night enuresis is seen in some children with
encopresis (fecal soiling). Rarely does a neurological
lesion produce fecal incontinence without a disturbance in bladder control.
Vomiting
Bilious vomiting can indicate intestinal obstruction in
the newborn. Vomiting associated with pain in adults
can indicate obstruction.
Chapter 10 • Constipation
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113
Pain
Chronic recurrent abdominal pain is commonly present
in constipation. Pain is intermittent and can be localized to the periumbilical region. Crampy lower abdominal pain is usually caused by bowel distention
which can result from IBS, intermittent obstruction, or
adhesions. Noncrampy dull pain in the left abdomen is
associated with diverticulosis. Pain on defecation can
indicate an anal or a rectal lesion such as hemorrhoids
or anal ssures.
Bleeding
Bright red blood in the stool indicates hemorrhoids,
ssure, or possible rectal mass. Black stools can indicate bleeding from a site in the upper GI tract because
blood mixed with gastric acid makes the stools appear
black. Brisk bleeding is uncommon with hemorrhoids
and requires immediate thorough investigation.
Color
Red stools can be the result of using laxatives of vegetable origin or ingestion of foods such as red beets. A
black or very dark brown color can be caused by drugs
such as iron and bismuth, both of which contribute to
constipation.
secondary to painful defecation, with a resultant anal
ssure. Coercive bowel training, fear of the toilet, or
reactive voluntary withholding of bowel movements
can also cause this condition.
History of Delayed Passage of Meconium Stool
Such a history can indicate congenital aganglionic
megacolon (Hirschsprung disease).
Change in Diet
Cow’s milk is a common cause of constipation in
young children who have been on breast milk or
formula.
Toilet Training
Some children develop stool withholding when toilet
training is initiated.
History of Urinary Frequency
Urinary frequency, enuresis, and urinary tract infections can be the result of constipation. Fecal soiling can
cause urinary tract infection by the introduction of the
fecal ora. Further, an enlarged dilated rectum can
push on the bladder, causing a frequent need to urinate.
If this is a child, is there anything else I need to
consider?
Key Questions
l
Is there crying with defecation?
l
Is there fecal soiling of underpants?
l
If an infant: Is there a history of delayed passage of
meconium stool?
l
Has the child begun to drink milk?
l
Has the child recently started toilet training?
l
Does the child have urinary frequency?
Crying With Defecation
Small children with constipation will cry with movement when a ssure is present. With large hard stools,
the child will not want to defecate because of the pain
and will do stool-holding mannerisms such as sitting
and standing still.
Fecal Soiling of Underpants
Repeated fecal soiling, from involuntary passage of
small amounts of feces into the underpants of children
older than age 4, is consistent with encopresis. This is
generally caused by functional megacolon secondary
to chronic constipation. This constipation is usually
Is there a family history or genetic predisposition?
Key Question
l
Is there a family history of constipation or IBS?
Genetic predisposition to constipation seems to exist.
It is common for more than one family member to have
a history of chronic constipation or IBS.
DIAGNOSTIC REASONING: FOCUSED
PHYSICAL EXAMINATION
Plot Growth Curve in Children
Slow growth can indicate congenital aganglionic megacolon. Incorrect formula mixing, underfeeding, starvation, and anorexia nervosa can rst be recognized by a
report of constipation.
Perform Abdominal Examination
Observe abdominal contour, looking for distention.
Abdominal distention is frequently not marked in patients with functional constipation but can be present
with other causes. Auscultate for bowel sounds. Silent
or abnormal bowel sounds can indicate an organic
cause such as obstruction. On palpation, stool can
be felt as mobile, nontender masses in the left lower
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Chapter 10 • Constipation
quadrant (LLQ). Firm, rubbery masses of stool palpable in the right lower quadrant (RLQ) in newborns can
indicate meconium ileus. Palpable abdominal masses
or organomegaly point to an organic cause. Note tenderness, which can indicate an organic cause, although
a tender bowel can be palpable in IBS. Inspect the
sacral region of the back. The presence of dimpling
could indicate a spinal deformity contributing to the
constipation.
Look for hernias. Large abdominal wall hernias can
interfere with the ability to generate the intra-abdominal
pressure that is required to initiate defecation.
Perform Digital Rectal Examination
On perianal inspection, look for skin excoriation,
skin tags, ssures, strictures, tears, or hemorrhoids,
any of which can cause painful defecation. Early ssures have the appearance of supercial erosions.
More advanced lesions are linear or elliptical breaks
in the skin. Long-standing ssures are deep and
indurated. Internal ssures are seen when the anal
sphincter relaxes as the examining nger is withdrawn. To examine for a ssure in a child, place the
infant/child in the knee–chest position and spread
the buttocks to reveal the mucocutaneous junction of
the anus.
Look for rectal prolapse and feel for a rectocele,
which might interfere with defecation. A normal anal
sphincter with an empty rectal ampulla can indicate
Hirschsprung disease. In functional constipation, expect to nd a large dilated rectum full of stool. Assess
sphincter tone, both at resting and with a squeezing
effort. Sphincter tone is increased in functional problems and strictures but is decreased in neurological
diseases. The presence of a mass in the rectum indicates an impaction or obstructive lesion. A pilonidal
dimple is seen with spinal bida occulta.
Table 10-1
Supercial and Deep Tendon
Reexes and Spinal Level
Tested
REFLEX SPINAL LEVEL TESTED
SUPERFICIAL
Upper abdominal T7, T8, T9
Lower abdominal T10, T11
Cremasteric T12, L1, L2
DEEP
Biceps
Brachioradial C5, C6
Triceps C6, C7, C8
Patellar L2, L3, L4
Achilles S1, S2
C5, C6
Perform a Focused Neurological Examination
Test relevant deep tendon and supercial reexes. Interruption of T12-S3 nerves causes loss of voluntary
control of defecation (Table 10-1).
LABORATORY AND DIAGNOSTIC STUDIES
Fecal Occult Blood Test
A positive guaiac-based fecal occult blood test (gFOBT)
indicates blood in the stool, which can be the result of
ulcerative or malignant lesions. The sensitivity of this
test in detecting colorectal cancers and adenomas ranges
from 50% to 90%. It is an inexpensive and noninvasive
method to screen for bleeding lesions. Three days of serial testing can be done using stool cards at home that
are returned by mail for analysis. Annual gFOBT, beginning at age 50 years, is one of the recommended screening tests for colon cancer. The Evidence-Based Practice
box describes the current recommendations.
EVIDENCE-BASED PRACTICE
The American Cancer Society, U.S. Multi-Society Task Force
on Colorectal Cancer, and the American College of Radiology
jointly developed consensus guidelines for colorectal cancer
screening in asymptomatic adults 50 years of age and older
who are at average risk. The screening tests were grouped into
those that primarily detect cancer and those that can detect
both cancer and adenomatous polyps, which provides the
opportunity for cancer prevention through polypectomy. The
panel supports screening primarily for cancer prevention.
Data from Levin B, Lieberman DA, McFarland B, et al: Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps:
A joint guideline from the American Cancer Society, the U.S. Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology,
Gastroenterology 134: 1570, 2008.
Screening for Colon Cancer
Specific recommendations may be found at www.cancer.org/
cancer/colonandrectumcancer/moreinformation/colonandrectumcancerearlydetection/colorectal-cancer-early-detectionacs-recommendations.
The U.S. Preventive Services Task Force (USPSTF) concluded that the evidence is insufficient (I) to assess the benefits and harms of computed tomographic colonography and
fecal DNA testing as screening modalities for colorectal cancer
(www.uspreventiveservicestaskforce.org/uspstf/uspscolo.htm).
Chapter 10 • Constipation
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115
Fecal Immunochemical Test
Fecal immunochemical test (FIT), also called immunochemical FOBT (iFOBT), can be used as an alternative to FOBT. FIT uses antibodies to human globin
to detect a specic portion of a human blood protein
and does not react with nonhuman hemoglobin or
peroxidase, so food restrictions before the test are not
necessary. Immunochemical FOBTs are also more
specic for lower GI tract bleeding because they target the globin portion of hemoglobin, which does not
survive passage through the upper GI tract. This test
is done essentially the same way as conventional
FOBT but is more specic and reduces the number of
false positive results. Vitamins or foods do not affect
the FIT and some forms require only one or two stool
specimens.
Fecal/Stool DNA
Cells from precancerous polyps and cancerous tumors
are shed in the stool and contain recognizable DNA
markers. A stool DNA test can identify several of these
markers, indicating the presence of precancerous polyps or colon cancer.
Complete Blood Count
Obtain a complete blood count (CBC) when you suspect bleeding. Hematocrit and hemoglobin levels will
be below the expected reference range with a bleeding
lesion.
Serum Electrolytes
Severely ill patients can develop hypokalemia and hypercalcemia, which are causes of constipation. Patients
on thiazide diuretics can develop hypokalemia and
subsequent constipation.
Serum Thyroid-Stimulating Hormone
An elevated thyroid-stimulating hormone (TSH) level
may be suggestive of hypothyroidism, which can be a
cause of constipation. Screen for elevated TSH levels
in people with other symptoms suggestive of hypothyroidism such as sparse, coarse, dry hair; hirsutism; dry
skin; or hoarse speech.
Urinalysis
A urinalysis and culture should be done if a child
has an associated rectosigmoid impaction because of
encopresis.
in the anus or rectum. It enables a view of the im-
mediate internal anal canal that is not possible
on manual digital rectal examination. A handheld
anoscope is warmed, lubricated, and slowly eased
into the anus while the patient bears down to relax
the external sphincter muscle. A light source is
necessary; a head lamp is preferable. Anoscopy may
not be possible initially with a ssure or abscess
because of the pain. However, it should be per-
formed on a follow-up visit to detect IBD or rectal
cancer.
Flexible Sigmoidoscopy and Colonoscopy
These tests are indicated for patients in whom conserva-
tive treatment fails, for people older than age 50 years or
with new-onset constipation, and for those with anemia
or fecal occult blood. Colonoscopy is indicated for the
patient with rectal bleeding.
Barium Enema
This contrast technique can be used to detect divertic-
ula, polyps, and masses. It is also used to determine the
extent of dilated bowel in megacolon. The barium en-
ema in children is reserved to rule out Hirschsprung
disease. A barium enema is contraindicated if entero-
colitis is suspected.
Colon Transit Studies
Colon transit studies are useful for patients with
severe chronic constipation that responds poorly to
treatment.
Anorectal Manometry
This test measures the pressure of the anal sphincter
muscles, the sensation in the rectum, and the neural
reexes that are needed for normal bowel movements.
The manometry probe, a thin tube of soft plastic or
rigid metal, is inserted into the rectum about 4 inches
and then slowly withdrawn halfway. As the probe is
withdrawn, the transducer continuously records the
pressure at different points. Alternatively, the pressure
can be measured with a balloon manometry system,
a hollow metal cylinder to which three balloons are
attached to measure pressure during anal contraction. A
balloon at the tip of the probe is inated to determine
whether the patient feels a sensation of rectal fullness
and an urge to defecate.
Anoscopy
Anoscopy is indicated if digital rectal examination
detects hemorrhoids, ssures, strictures, or masses
DIFFERENTIAL DIAGNOSIS
Despite the high prevalence of constipation, only a
small number of adults or children with constipation
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Chapter 10 • Constipation
have a signicant abnormality. In otherwise healthy individuals, rst consider functional causes, particularly
dietary, uid, bowel, and laxative habits. In adults,
depression can be associated with constipation.
Simple Constipation
Typically individuals with simple constipation report a
diet low in ber and bulk and/or inadequate uid intake. A sedentary lifestyle is common. They also often
report pain before and with bowel movements because
of the hard, dry nature of the stools. Patients can also
report loss of appetite. The physical examination of the
abdomen and rectum is normal. It may be possible to
feel fecal masses in the colon and rectum. No diagnostic workup is needed unless the patient does not respond to therapy.
Functional Constipation
Functional causes of constipation include poor bowel
habits; inadequate intake of dietary ber, bulk, and
uids; and chronic use of laxatives. Patients may report
straining during defecation, hard or lumpy stools, and
sensations of incomplete evacuation and/or anorectal
obstruction. The abdomen may or may not be distended. The external sphincter is intact.
Functional constipation is seen in children who
have large, hard stools that become difcult or painful
to pass. The resulting fecal retention sets up a cycle in
which the sensitivity of the defecation reex and the
effectiveness of peristalsis lessen. Watery stool from
the proximal colon soils the underwear. On physical
examination, stool is present in the LLQ, and the rectum is dilated and lled with packed stool. The external
sphincter is intact.
Irritable Bowel Syndrome (IBS)
IBS is common in adults, with onset usually in young
adulthood. The presenting symptoms can be either diarrhea or constipation. Alternating episodes of each is
characteristic of IBS. Mucus in the stools is common.
Abdominal pain often occurs, usually in the LLQ, and
the bowel may be tender to palpation. A tender bowel
may be palpable (see Chapter 12).
Fecal Impaction
Fecal impaction is common in older adults and in those
who are conned to bed. The passage of hard stools at
3- to 5-day intervals can occur. Some people with impaction have continuous diarrhea-like passage of stools
and can experience incontinence. Stools can be of
small caliber, sometimes described as toothpaste-like.
On rectal examination, large quantities of hard feces
will be palpable in the rectal ampulla. On abdominal
examination, feces-lled bowel may be palpable.
Idiopathic Slow Transit
This condition is most common in older people, especially
those who are less active and have inadequate dietary ber
and uid intake. These patients experience decreased
stool frequency; stools are typically dry and hard.
Hirschsprung Disease (Congenital Aganglionic
Megacolon)
Hirschsprung disease is present from birth and is usually detected in young children. Delayed passage of
meconium stool can indicate Hirschsprung disease in
infants. Children with Hirschsprung disease do not
have an urge to defecate because the stools accumulate
proximal to the lower portion of the rectum where the
proprioceptors for defecation are located. Evidence of
stiffening, squeezing, and crying indicates stool is being propelled to the rectum. On examination the rectal
ampulla is empty.
Secondary Constipation From Anorectal Lesion
Because defecation is painful with an anorectal lesion,
the patient suppresses it. With the eventual passage of
hard stools, the patient can report blood on the surface
of the stool, on the toilet paper, or in the toilet. On
digital rectal examination, look for hemorrhoids (rare
in children), ssures, tears, or abrasions.
Drug-Induced Constipation
Drug-induced constipation is consistent with a history
of chronic laxative use or taking medications that can
produce constipation. It occurs most often in older
adults. Abdominal and rectal examinations are usually
normal.
Tumors
Tumors are uncommon in children, but the frequency
increases in the population over the age of 40. Colicky
abdominal pain and distention can occur in people with
bowel tumors. People with rectosigmoid tumors may
report rectal discomfort, stool leakage, urgency, and
tenesmus. The patient may report rectal bleeding or
blood in the stool. Stool may test positive for occult
blood. An abdominal mass may be palpable. Older
adult patients who present with constipation, anemia,
anorexia, and weight loss are at high suspicion for
colorectal cancer. Constipation occurs in less than onethird of people with colon cancer; diarrhea is more
common. Onset is recent, and there can be progressive
narrowing of stool caliber.
Chapter 10 • Constipation
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117
DIFFERENTIAL DIAGNOSIS OF
Common Causes of Constipation
CONDITION HISTORY PHYSICAL FINDINGS DIAGNOSTIC STUDIES
Simple
constipation
Functional
constipation
Irritable bowel
syndrome (IBS)
Obstipation/
impaction
Slow transit Common in older adults; physical
Hirschsprung
disease
Anorectal
lesions
Drug induced History of chronic laxative use; history
Colorectal
cancer
CBC, Complete blood count; FIT, fecal immunochemical test; FOBT, fecal occult blood test; LLQ, left lower quadrant.
Low dietary fiber and bulk; inadequate
fluid intake; physical inactivity; pain
before and with bowel movements;
anorexia
Adults: bowel habits; chronic use of
laxatives. Straining during defecation,
hard or lumpy stools, a sensation of
incomplete evacuation and/or anorectal obstruction
Preschool and school-age children: history
of abdominal pain and stool soiling
Onset in young adulthood; alternating diar-
rhea and constipation; mucus in stools
Passage of hard stool at 3- to 5-day in-
tervals; diarrhea, small caliber stools;
common in those confined to bed
inactivity; decreased stool frequency;
stool dry and hard
Delayed passage of meconium at birth;
no urge to defecate
Rectal pain on defecation; history of
hemorrhoids; blood on stool, on toilet
tissue, or in toilet
of taking medications that produce
constipation
Recent onset: pain and abdominal dis-
tention, stool leakage, urgency; late
onset: weight loss, anorexia; rectal
bleeding; increased incidence over age
40; uncommon in children
Normal abdominal and
rectal examination; can
feel fecal masses in
colon and rectum
Abdomen may or may not
be distended. The external sphincter is intact.
Palpable stool in LLQ;
large dilated rectum
with packed stool; external sphincter intact
Can have tender, palpable
colon
Hard feces in rectal am-
pulla; may have palpable feces-filled bowel
Normal abdominal and
rectal examination
Empty rectal ampulla on
examination
On rectal examination:
hemorrhoids, fissures,
tears, abrasions; increased sphincter tone
Normal rectal and ab-
dominal examinations
Can have palpable
abdominal mass or
organomegaly
None if resolved; consider
colonoscopy/sigmoidoscopy, anorectal manometry, colon transit studies
if not resolved
Abdominal radiography,
unprepped barium
radiography
Colonoscopy/sigmoidoscopy
if indicated
Colonoscopy/sigmoidoscopy
if indicated
Colonoscopy/FOBT or FIT
to rule out tumors; consider anorectal manometry, colon transit studies
Colonoscopy
Anoscopy
None if resolved;
consider colonoscopy/
sigmoidoscopy, barium
enema if not resolved
CBC, FOBT, FIT, fecal/stool
DNA; colonoscopy
References and Readings
American Gastroenterological Association (AGA): American Gastro-
enterological Association Medical Position Statement: Guidelines
on Constipation, Gastroenterology 144:211, 2013.
Basson MD: Constipation, updated Sept 23, 2013. Retrieved from
http://emedicine.medscape.com/article/184704-overview.
Blackmer HB: Constipation in the pediatric patient: An overview
and pharmacologic considerations, J Ped Health Care 24:6,
2010.
Bleser SD: Chronic constipation: Let symptom type and severity
direct treatment, J Fam Pract 55:587, 2009.
Coughlin E: Assessment and management of pediatric constipation
in primary care, Pediatr Nurs 29:296, 2004.
Har AF, Crofe JM: Encopresis, Pediatr Rev 31(9):368, 2010.
Jamshed N, Lee Z-E, Olden KW: Diagnostic approach to chronic
constipation in adults, Am Fam Physician 84:299, 2011.
McCallum I, Ong S, Mercer-Jones MM: Chronic constipation in
adults, BMJ 338:763, 2009.
Rao SS: Constipation: Evaluation and treatment, Gastroenterol Clin
North Am 32:659, 2003.
Rao SS, Ozturk R, Laine L: Clinical utility of diagnostic tests for constipa-
tion in adults: A systematic review, Am J Gastroenterol 100:1605, 2005.
Rome Foundation: Rome III Diagnostic criteria for functional gastroin-
testinal disorders, 2014. Retrieved from http://www.romecriteria.org/
criteria/.
Tobias N: Management principles of organic causes of childhood
constipation, J Pediatr Health Care 22:12, 2008.
Walia R: Recent advances in chronic constipation, Current Opinion
Pediatr 21:645, 2009.
Youssef NN: Adolescent constipation: Evaluation and management,
Adolesc Med Clin 15:37, 2004.
Youssef NN, Di Lorenzo C: Childhood constipation: Evaluation and
treatment, J Clin Gastroenterol 33:199, 2001.
CHAPTER
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11
ough is one of the most common symptoms for
C
which patients seek health care. Cough occurs
when inspiration is followed by an explosive expiration, promoting clearance of secretions and foreign
bodies from the airways, and is usually the result of
a reex initiated by stimulation of the sensory nerve
endings beneath and between the epithelium of the
larynx and tracheobronchial tree. There are three
mechanisms that trigger cough: (1) rapidly adapting
receptors activated by punctate mechanical stimuli,
airway smooth muscle contraction, and gastric acid,
(2) C-bers that respond to various chemicals, and
(3) cough receptors that are stimulated by mechanical stimuli such as postnasal drip.
The reex stimulation follows the vagus nerve to
the “cough center,” which is located in the medulla
oblongata of the brainstem. However, other anatomical
locations can be stimulated and initiate the cough
reex, including the pleura, pericardium, ear canals,
esophagus, and stomach. The cough reex is absent in
very young infants. Effective coughing may also be
impossible in emaciated individuals, in patients whose
respiratory musculature is weak or paralyzed, and in
those with massive ascites.
Although most coughs are a symptom of minor
upper respiratory infections (URIs), such as the common cold, a persistent cough can greatly affect a
patient’s quality of life and ability to sleep. Keep
in mind, however, that a cough in a patient in acute
Cough
distress can signal a life-threatening problem such
as foreign body aspiration with occlusion of airway,
severe asthma, escalating heart failure, or pneumonia.
DIAGNOSTIC REASONING: FOCUSED
HISTORY
What type of cough is this?
Key Question
l
How long have you had a cough?
Duration
Cough can be characterized by the following three
categories of duration: (1) acute, less than 3 weeks;
(2) subacute, lasting 3 to 8 weeks; and (3) chronic, lasting more than 8 weeks. A cough of recent onset is most
often the result of viral or bacterial infection in the respiratory system. Allergies can also precipitate acute
onset of cough in both children and adults. Cough lasting a longer duration (more than 3 weeks) is more
likely caused by chronic lung or heart disease such as
chronic obstructive pulmonary disease (COPD), cystic
brosis, chronic bronchitis, asthma, heart failure, or
an infectious process such as pertussis and chronic
sinusitis. Gastroesophageal reux disease (GERD) and
a foreign body in the ear canal should also be considered as a possible cause of cough in both adults and
children.
EVIDENCE-BASED PRACTICE
There is a mismatch between patient expectations and reality,
for the natural history of acute cough illness (ACI). Patient
expectations are that ACI lasts 6 to 7 days and they often seek
care for antibiotics at 5 to 6 days. If they are prescribed antibiotics and begin to feel better 3 to 4 days later, the belief
Data from Ebell, MH, Lundgren J, Youngpairoj S: How long does a cough last? Comparing patients’ expectations with data from a systematic review
of the literature, Ann Fam Med 11: 5-13, 2011.
118
How Long Does a Cough Last Before a Patient Seeks Care?
that antibiotics helped is reinforced. Yet in reality the natural
history of acute cough would resolve without antibiotic treatment within 10 days. This mismatch suggests that clinicians
need to educate patients about the natural history of ACI to
reduce the demand for inappropriate antibiotic use.
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