Ischaemic proctitis and adventitial fibromuscular dysplasia of the superior rectal artery.

A case of ischaemic proctitis apparently caused by adventitial fibromuscular dysplasia of the superior rectal artery is reported and the results of a survey of 50 superior rectal and marginal arteries from post mortem and surgical cases are described. Abnormal musculature was demonstrated in varying degree in the adventitia of 28 of 50 asymptomatic patients. Our findings indicate that a spectrum of this vascular abnormality exists in the elderly which is rarely severe enough to contribute to symptomatic large bowel ischaemia.