Reports of solitary rectal ulcer syndrome (SRUS) from the United States are rare. A retrospective analysis of biopsy specimens over a period of 5 years yielded 12 patients who fulfilled the histopathologic criteria for this disorder. The clinicopathologic features of patients in this series are similar to those previously reported; the majority presented with solitary ulcerated or polypoid lesions located 4-18 cm from the anal margin. The initial clinical diagnosis was never SRUS; carcinoma and inflammatory bowel disease were considered most likely in one and three cases, respectively. Three patients had mucosal prolapse. Solitary rectal ulcer syndrome was the initial pathologic diagnosis in only four patients (33%). We conclude that SRUS is frequently underdiagnosed both clinically and pathologically in this country. The pathologist might be the first to suggest this diagnosis to the clinician by recognizing its characteristic histopathologic features.