Solitary Rectal Ulcer Syndrome

Solitary rectal ulcer syndrome (SRUS) is a benign disorder of defecation causing rectal mucosal ischaemic injury, with ulceration, polypoid or erythematous lesions on the anterior rectal wall.

• Incidence is about 1 per 100,000 per year, in young adults (20 to 40 years) with a slight female predominance.
• Mechanism: chronic straining, rectal intussusception or prolapse, paradoxical puborectalis contraction, digital evacuation, causing trauma and ischaemia.
• Ulcers are multiple in 20 to 30% and not always solitary. About 25% have no ulcer, only erythema or polyps.
• Histology: fibromuscular obliteration of the lamina propria, crypt distortion, thickened muscularis mucosae, with mucosal prolapse changes.
• Complications: bleeding, stricture, anaemia, pain, rare perforation, and risk of mistaken diagnosis as cancer or Crohn disease.

• Rectal bleeding, mucus discharge, straining, feeling of incomplete evacuation, tenesmus, digital evacuation, pelvic pain.
• Constipation, or sometimes diarrhoea with urgency.
• Some are asymptomatic and diagnosed incidentally.
• Examination: tender anterior rectal mass, ulcer on digital rectal examination.

• Flexible sigmoidoscopy or colonoscopy: ulcer 1 to 5 cm in the anterior rectal wall 7 to 10 cm from the anal verge, or polypoid, erythematous patches. Biopsy to exclude neoplasia and inflammatory bowel disease.
• Defecography (evacuation proctography or MR defecography) shows intussusception, rectal prolapse, rectocele, non relaxing puborectalis.
• Anorectal manometry and balloon expulsion test for dyssynergic defecation.
• Endoanal ultrasound for sphincter integrity.

• Behavioural: avoid straining, regulate toileting, stop digital evacuation, high fibre diet (25 to 30 g daily), fluids.
• Laxatives: psyllium 5 to 10 g twice daily, macrogol 17 g daily.
• Biofeedback therapy for dyssynergic defecation (5 to 6 sessions), healing in about 40 to 60%.
• Topical therapy: sucralfate enema 2 g twice daily, mesalazine suppository 1 g, or corticosteroid foam, with limited benefit. Topical sulfasalazine and fibrin sealant are reported.
• Botulinum toxin injection into the puborectalis (100 units) in selected cases.
• Surgery for failure of medical therapy, with prolapse: laparoscopic ventral mesh rectopexy (healing in about 70 to 80%), or resection rectopexy. Excision of the ulcer is generally not advised. Stoma only for refractory disease.
• Follow up with endoscopy for non healing ulcers.