General and Colorectal
CASE 20: inCreaSeD boWel FreQuenCy
anD reCtal bleeDing
history
A 40-year-old woman presents to the emergency department complaining of a 2-month history of bright red rectal bleeding, motions up to six times per day and cramping lower abdominal pains. She has lost 2 stone in weight. She finished a course of Augmentin for a chest infection 2 weeks ago. She had an appendicectomy at the age of 16 years with no other past history of note. She visited Thailand on a family holiday 3 weeks ago.
examination
The temperature is 37.5°C with a pulse rate of 98/min and a blood pressure of 140/70 mmHg. There is no lymphadenopathy. The abdomen is soft with tenderness to deep palpation in the left iliac fossa. Digital rectal examination shows soft stool with a small amount of bright red blood and mucus mixed in. Rigid sigmoidoscopy to 20 cm from the anal verge reveals bright red, friable rectal mucosa. A biopsy is taken.
INVESTIGATIONS
|
|
Normal |
haemoglobin |
13.2 g/dl |
11.5–16.0 g/dl |
mean cell volume |
86 fl |
76–96 fl |
White cell count |
5.9 × 109/l |
4.0–11.0 × 109/l |
platelets |
302 × 109/l |
150–400 × 109/l |
Sodium |
147 mmol/l |
135–145 mmol/l |
potassium |
4.8 mmol/l |
3.5–5.0 mmol/l |
urea |
6.9 mmol/l |
2.5–6.7 mmol/l |
Creatinine |
50 μmol/l |
44–80 μmol/l |
amylase |
68 iu/dl |
0–100 iu/dl |
aspartate transaminase (aSt) |
32 iu/l |
5–35 iu/l |
alkaline phosphatase (alp) |
74 iu/l |
35–110 iu/l |
gamma-glutamyl transferase (ggt) |
42 iu/l |
11–51 iu/l |
albumin |
37 g/l |
35–50 g/l |
bilirubin |
16 mmol/l |
3–17 mmol/l |
erythrocyte sedimentation rate (eSr) |
49 mm/h |
1–13 mm/h |
Questions
•What differential diagnoses would you consider?
•The biopsy suggests ulcerative colitis. What are the typical histological findings?
•How should the patient be managed acutely?
•What is the potential for malignant change associated with this condition?
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100 Cases in Surgery
ANSWER 20
!The main differential diagnoses for a patient with this history and symptoms
•Inflammatory bowel disease: Crohn’s disease or ulcerative colitis
•Infective diarrhoea: Shigella, Salmonella, Yersinia and Campylobacter
•Pseudomembranous colitis: secondary to antibiotic use
In view of the patient’s history, a biopsy of the rectal mucosa and stool sample should be sent. Microbiology can analyse the sample for an infective cause or test for Clostridium difficile toxin in cases of pseudomembranous colitis.
Ulcerative colitis occurs most commonly between the ages of 15 and 40 years, and usually involves the rectum then progresses more proximally. Typical histological changes include infiltration with acute and chronic inflammatory cells that is confined to the mucosa (unlike Crohn’s disease where changes are transmural). In severe cases there is fissuring and transmural inflammation, making it difficult to distinguish Crohn’s disease from ulcerative colitis on the basis of histology.
Medical management is aimed at controlling inflammation and reducing symptoms. In cases of severe colitis, nutritional support and correction of electrolyte disturbances may also be required. Corticosteroids can be used to induce remission, and salicylic acid derivatives employed to maintain remission – these can be administered as enemas or suppositories where the disease only involves the rectum. If diarrhoea is particularly problematic, agents such as codeine phosphate and loperamide may be considered.
The potential for malignant change is relatively high with long-standing ulcerative colitis and the risk in patients with pancolitis is approximately 3 per cent after 10 years. The risk of developing mucosal dysplasia increases with time, and surveillance should commence after 7 years. Colonoscopy and biopsy are performed every 2–3 years. If dysplasia is detected, the patient should undergo total colectomy with end ileostomy.
KEY POINTS
•long-standing ulcerative colitis carries an approximate 3 per cent risk of malignant change after 10 years.
•Colonoscopy and biopsy are performed every 2–3 years.
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