In the solitary rectal ulcer syndrome, rectal ulceration typically occurs on the anterior wall of the rectum, 5 cm to 10 cm from the anal margin. Although the pathogenesis is debated, the majority of patients have an occult or overt rectal prolapse. Other causes include direct trauma due to rectal digitation and perhaps rectal ischemia caused by atherosclerosis. In patients with rectal prolapse, straining at defecation causes ischemia at the apex of the prolapse because of traction on submucosal blood vessels or strangulation of the prolapsing mucosa by the puborectalis muscle. Symptoms include rectal bleeding, excess rectal mucus, constipation, tenesmus and incomplete defecation. The endoscopic appearance ranges from single to multiple ulcers, sometimes associated with patches of polypoid, hyperemic mucosa. The differential diagnosis includes rectal cancer, Crohn’s disease, infectious ulcers and the use of non-steroidal, anti-inflammatory suppositories. Rectal biopsies are usually helpful and show replacement of the lamina propria with disordered smooth muscle bundles and fibrous tissue and thickening of the muscularis mucosa. There are no controlled trials of therapy but many patients improve, either spontaneously or with management of constipation. Surgical treatment using rectopexy or rectopexy with sigmoid colectomy may also be helpful in patients with persistent ulceration in the presence of a prolapse. The patient illustrated below was a young woman, aged 21, who was referred for evaluation of rectal bleeding. She described episodes of painless rectal bleeding from the age of 5 years. Blood was usually bright and was largely seen on the toilet paper after straining. She normally passed 2 or 3 formed stools each day without urgency or incontinence. On rectal examination, a nodule was palpated on the anterior wall of the rectum. With retroflexion of the colonoscope in the rectum, there was a nodular area, 3 cm in diameter, with a smooth red edge and central ulceration (Fig. 1). Biopsies revealed surface ulceration, patchy acute inflammation and replacement of the lamina propria by endothelial cells and vertically oriented smooth muscle bundles (Fig. 2). She has been advised to avoid straining at defecation and has been treated with bulk-forming supplements. Contributed by