Clinical Presentation

A 29-year-old woman presents with abdominal cramping.

Lateral proctography shows plaquelike crenulations (arrow) of a focal portion of the anterior wall of the rectum, which appear to spare the mucosa but involve the serosa and submucosa. The remainder of the rectum appears normal.

Differential Diagnosis

• Endometriosis: This is the classic consideration for plaquelike crenulations of the anterior margin of the rectosigmoid colon in a young woman. This appearance is consistent with submucosal invasion by serosal implants of endometrium.

• Abscesses: