Solitary Rectal Ulcer Syndrome (SRUS)

See Anorectal Physiology Testing and Rectal Prolapse (Procidentia) — SRUS overlaps mechanistically with internal rectal prolapse. Content below is from a textbook reference chapter (Sabiston Ch52 - Pelvic Floor Disorders & Constipation), not primary literature.

Overview

A rare, chronic benign disorder characterized by a combination of symptoms, clinical findings, and histologic abnormalities. Despite the name, 20% of patients have a single ulcer while 40% have multiple ulcers; the remainder have nonspecific lesions such as hyperemic mucosa or pseudopolyps.

Disorder of young adults (30–40 years), with a slight female predominance. Multifactorial cause, including internal rectal prolapse and abnormal/paradoxical contraction of the puborectalis muscle — both conditions cause trauma and compression of the anterior rectal wall on the upper anal canal during straining and defecation, with resulting mucosal ischemia and, in some cases, ulceration.

Symptoms

Rectal bleeding, prolonged excessive straining, incomplete defecation/tenesmus, mucous discharge, perineal and abdominal pain, and constipation. Up to a quarter of patients are asymptomatic.

Diagnosis

Physical exam and anoscopy demonstrate an intrarectal prolapse and a 1–1.5 cm ulcer of the anterior rectal wall, 3–10 cm from the anal verge — sometimes difficult to differentiate from a rectal cancer on visual exam alone. Histologic examination of biopsies shows characteristic findings that differentiate SRUS from cancer and other inflammatory lesions (IBD, ischemic colitis, infectious proctitis): fibromuscular obliteration of the lamina propria, hypertrophied muscularis mucosae with muscular fibers between the crypts, and glandular crypt abnormalities.

Management

For patients with mild-to-moderate symptoms and no significant mucosal prolapse, medical treatment is usually effective: patient education and behavioral modification, high-fiber diet, stool softeners and bulking laxatives, avoidance of straining and/or anal digitation, minimizing time on the toilet, and use of sucralfate, corticosteroid, and/or mesalamine enemas.

Surgery is rarely indicated, reserved for highly symptomatic patients absolutely unresponsive to medical treatment. Surgical options include local excision of the ulcer, treatment of the rectal prolapse (see Rectal Prolapse Repair) if present, or a defunctioning stoma for patients who failed other options. Unfortunately, many patients with SRUS continue to have symptoms of anorectal dysfunction regardless of treatment.

Open items / gaps

• No primary trial data on medical therapy efficacy or surgical outcome comparisons.
• The “many patients continue to have symptoms regardless of treatment” note is a notable but unquantified caveat — worth flagging to patients in counseling even without a specific number to cite.