Background: Solitary rectal ulcer syndrome (SRUS) is an uncommon although benign defecation disorder. The aim of this study was to evaluate the variable endoscopic manifestations of SRUS and its association with other diseases.Methods: All the patients diagnosed with SRUS histologically from January 1990 to February 2011 at The Aga Khan University, Karachi were included in the study. The medical records were reviewed retrospectively to evaluate the clinical spectrum of the patients along with the endoscopic and histological findings.Results: A total of 116 patients were evaluated. The mean age was 37.4 ± 16.6 (range: 13-80) years, 61 (53%) of the patients were male. Bleeding per rectum was present in 82%, abdominal pain in 49%, constipation in 23% and diarrhea in 22%. Endoscopically, solitary and multiple lesions were present in 79 (68%) and 33 (28%) patients respectively; ulcerative lesions in 90 (78%), polypoidal in 29 (25%), erythematous patches in 3 (2.5%) and petechial spots in one patient. Associated underlying conditions were hemorrhoids in 7 (6%), hyperplastic polyps in 4 (3.5%), adenomatous polyps in 2(2%), history of ulcerative colitis in 3 (2.5%) while adenocarcinoma of colon was observed in two patients. One patient had previous surgery for colonic carcinoma.Conclusion: SRUS may manifest on endoscopy as multiple ulcers, polypoidal growth and erythematous patches and has shown to share clinicopathological features with rectal prolapse, proctitis cystica profunda (PCP) and inflammatory cloacogenic polyp; therefore collectively grouped as mucosal prolapse syndrome. This may be associated with underlying conditions such as polyps, ulcerative colitis, hemorrhoids and malignancy. High index of suspicion is required to diagnose potentially serious disease by repeated endoscopies with biopsies to look for potentially serious underlying conditions associated with SRUS.