Colonoscopic diagnosis of minimal change colitis in patients with a normal sigmoidoscopy and normal air-contrast barium enema.

8 patients with normal sigmoidoscopic appearances and normal results by high-quality air contrast barium enema had substantial or total colitis diagnosed for the first time at colonoscopy performed within a month of the radiological examination. Colitis was confirmed in all 8 patients by histological examination of biopsy specimens. Barium enema radiographs were independently reviewed by three experienced observers who also reviewed other normal and abnormal radiographs. One observer regarded all 8 sets of radiographs from the patients with colitis as being of normal appearance, and 4 patients were reported as having normal radiographs by all three observers. All 7 of the rectal biopsy specimens taken showed histological features of inflammatory bowel disease. This emphasises the importance of performing a rectal biopsy in patients with gastrointestinal symptoms of unknown cause.