Following a thorough history and discussion with the patient, a general and abdomi­nal examination is performed. A routine digital rectal examination should be per­formed on all patients presenting with anorectal or lower gastrointestinal symptoms. After gaining consent, the patient is placed in a comfortable position for examina­tion of the perianal region, perineum, anus and rectum. The left lateral decubitus position is most commonly used, but patients can also be examined in the genucu­bital or lithotomy position. It is important to obtain consent and ensure patient com­fort and dignity, optimum lighting, and the presence of a chaperone. Parting the buttocks allows for adequate inspection, and here the skin should be examined for dermatological disease and external stigmata of perianal or gastrointestinal disease. The surgeon should specifi cally look for any previous scars, any swellings or ulcer­ation, external fi stula openings on the skin, and any obvious pus, mucus, or bloody discharge. A closer look at the anoderm may reveal the characteristic ulcer of an anal fi ssure. The patient should be asked to strain, looking for rectal prolapse, pro­lapsing hemorrhoids or anal polyps, and perineal descent.

Fissure in ano is a common and problematic benign anorectal condition, which makes up 15 % of proctology consultations [ 43 ]. The condition is defi ned as a linear tear or ulcer in the anorectal squamous epithelium that occurs beyond the dentate line, at the anal verge. A chronic anal fi ssure is one that persists for more than 6 weeks despite medical management and may have the classic features of rolled edges, exposure of the internal anal sphincter fi bers, and a sentinel tag or anal papilla. Fissures are usually in the posterior midline, but can also be found anteriorly, later­ally, or in multiple locations. The location of the fi ssure may suggest a cause, with lateral fi ssures suggesting an underlying chronic disease process such as Crohn’s, ulcerative colitis, syphilis, tuberculosis, leukemia, cancer, or HIV. It is hypothesized that hypertonia and relative sphincter hypoperfusion result in ischemia of the poste­rior anal canal which causes pain and poor wound healing associated with a chronic anal fi ssure. This may be further exacerbated by recurrent minor anal trauma.

The fi rst steps to treating any acutely symptomatic fi ssure in ano are conserva­tive, with analgesia, stool softeners and sitz baths. Many will heal spontaneously; however, if that fails, topical ointments which act to reduce internal anal sphincter tone and improve local blood fl ow such as nitroglycerine, diltiazem, or nifedipine are used. Surgical treatment options include injection of Botox, fi ssurectomy, lateral internal sphincterotomy (LIS), and anal advancement fl aps. Lateral internal sphinc­terotomy can be performed using an open or closed technique and involves a con­trolled division of the internal sphincter. In LIS the internal sphincter is divided from its caudal edge, to a variable proximal distance, but no further than the dentate line. Over-extensive cutting can lead to incontinence.

The anal cushions are physiological highly vascular structures, present in all indi­viduals, and located above the dentate line at the transition zone. Their vascular nature enables them to vary in size and they become engorged with blood during periods of raised intra-abdominal pressure. This aids closure of the anal canal, con­tributing to the maintenance of continence [ 44 ]. The vascular cushions consist of the lining mucosa, the underlying vascular plexus, smooth muscle, and the connective