Idiopathic proctitis. I. The morphology of proximal colonic mucosa and its clinical significance.

A group of 31 patients with idiopathic proctitis were colonoscoped while they were symptomatic. Multiple mucosal biopsies were taken from the transverse, descending, and sigmoid colon and from the rectum. While visualization by colonoscopy revealed abnormalities limited to the most distal 18-20 cm of the colon, microscopic abnormalities were frequently seen in more proximal locations. Analysis of clinicopathological data indicates that there is good correlation between the extent of microscopic mucosal abnormalities and the clinical course. Patients with abnormalities limited to the rectum generally responded well to conventional treatment while patients with more proximal involvement were refractory to such therapy.