A pathophysiologic study of diversion proctitis.

Diversion proctitis occurs with variable frequency after exclusion of the fecal stream. Its importance lies in the inability to differentiate it from other types of proctitis that may result in inappropriate therapy and a reluctance to recommend stoma closure. The effect of fecal diversion (n = 18) and restoration of intestinal continuity (n = 10) on human rectal mucosa in patients without inflammatory intestinal disease has been prospectively evaluated. Fecal diversion was associated with macroscopic inflammation in 55 percent of the patients and histologic inflammation in 72 percent, with a variable incidence of aphthoid ulceration, crypt abscess formation and submucosal nodularity. Restoration of continuity was associated with improvement in histologic features in all patients, but the mucosa returned to normal in only 50 percent of the patients. Onset or resolution of diversion proctitis was not associated with any significant changes in colonic cellular proliferation, glycoprotein synthesis or mucosa-associated or luminal flora. The only diagnostic feature of defunctioned proctitis remains its resolution on reintroducing the fecal stream.