A pain in the rear

A 79-year-old, non-insulin-dependent diabetic woman presented with severe pain in the rectum and urgency. A year previously she had been seen because of alternating constipation and diarrhoea. Rectal examination and sigmoidoscopy were normal, but she had a distended bladder and was subsequently catheterized. and this had become permanent. She had had a hysterectomy and bilateral salpingo-oöphorectomy after intracavity radium for carcinoma of the body of the uterus 13 years before.

Examination revealed a lax anus, soft stool, and a soft mass behind the rectum. Sigmoidoscopy was again normal.

Pelvic ultrasound was performed after filling the bladder with saline (Fig. 1). This was followed by a barium enema (Fig. 2). A plain radiograph of the pelvis after barium had cleared is also shown (Fig. 3).