A patient with rectal ulcer with severe stenosis presenting with perforated peritonitis.

We report a patient with rectal ulcer with severe stenosis, who underwent urgent surgical treatment for perforated peritonitis. The 54-year-old man suddenly developed cramping abdominal pain and fever while hospitalized, with signs of peritoneal irritation. An emergency laparotomy was performed, and severe stenosis of the rectum and a perforated lesion on the oral side approximately 10 cm distant from the stenosis were found, with massive abdominal purulent fluid. He was treated by rectosigmoid colon resection with transverse colon loop colostomy. Histopathologically, the stenosis was caused by ulceration extending to all muscular layers of the rectum, with inflammatory changes. Benign rectal stenosis is so rare that differential diagnosis from malignancy may be difficult when there are inflammatory changes in the surrounding tissues. However, it is necessary to keep in mind the likelihood of this disease in differentiation from rectal cancer.