We found colitis in 11 of 14 children, 4 months to 7 yr after surgical diversion of the colon for chronic intestinal pseudo-obstruction. Colonoscopic examination was incidental during placement of a catheter for colon manometry and transit studies. All 14 children had complained of diffuse, poorly localized abdominal pain, but only three had a history of bloody stools. Diversion colitis had not previously been suspected in six of eight affected children without hematochezia. Biopsies showed a nonspecific acute and chronic inflammation and/or nodular lymphoid hyperplasia. There was no correlation between the duration of the colonic diversion and the severity of the colitis. Diversion colitis may be an indolent inflammatory nidus and a potential cause for repeated bacteremia, abdominal pain, and bleeding.