Solitary Rectal Ulcer Syndrome Mimicking Ulcerative Colitis: A Case Report.

Solitary rectal ulcer syndrome (SRUS) is a benign rectal disorder associated with abnormal defecation and mucosal prolapse. Its clinical and endoscopic features may mimic inflammatory bowel disease (IBD). We report the case of a 28-year-old woman with longstanding obstructed defecation who presented with recurrent bloody mucus discharge and severe iron-deficiency anemia (hemoglobin 6.6 g/dL), which was treated with intravenous iron infusions. C-reactive protein was normal, whereas fecal calprotectin was markedly elevated. Initial colonoscopy showed erythematous and congested mucosa extending from the anal verge to 20 cm, with a large ulcer, raising suspicion of ulcerative colitis. However, the initial biopsies were inconclusive. Following clinical worsening, repeat colonoscopy revealed a 5-cm elevated rectal lesion with central ulceration. Histological examination demonstrated epithelial loss, granulation tissue, villiform crypt changes, and characteristic fibromuscular hyperplasia of the lamina propria, establishing the diagnosis of SRUS. Magnetic resonance defecography revealed an anterior rectocele and internal rectal prolapse, while anorectal manometry demonstrated dyssynergic defecation. Conservative measures and biofeedback provided incomplete improvement, with persistent rectal bleeding. Given the documented internal rectal prolapse and refractory symptoms, laparoscopic ventral rectopexy was performed, resulting in a favorable postoperative clinical course with marked symptomatic improvement and normalization of hemoglobin to 13.7 g/dL. SRUS should be considered when inflammatory-appearing rectal lesions are not supported by histological evidence of IBD, particularly in patients with obstructed defecation.