Histological appraisal of ulcerative colitis fibreoptic colonoscope biopsy specimens.

The availability of the fibreoptic colonoscope with biopsy facilities has created new opportunities for the investigation of ulcerative colitis. Morphological assessment of the disease, which has hitherto been limited to observing changes in the mucosa of the sigmoid colon and rectum, can now be made on biopsy material obtained under direct vision from the large bowel above the level of the sigmoid. On the basis of 157 colonoscopic biopsies taken from 38 patients with endoscopic appearances of the disease is proposed. The classification is as follows: (i) active chronic phase without ulceration; (ii) active chronic phase with ulceration; (iii) quiescent chronic phase; (iv) healed chronic phase; (v) precancerous phase. Three degrees of severity (mild, moderate and severe) for each phase are recognized.