[Precancerous lesions of the colon and rectum].

Adenomatous polyp, adenomatosis coli and dysplasia in the inflammatory bowel disease are noted as precancerous lesions. 1) Adenomatous polyps are easily found by colonoscopy as protruded lesions and diagnosed by histopathological study. 2) Adenomatosis coli is easily diagnosed by barium enema and colonoscopy. Adenomatosis coli is accompanied with cancer frequently. As soon as adenomatosis coli is detected, we recommend surgery. IRA (total colectomy and ileorectal anastomosis) is mainly undertaken for adenomatosis coli. But when there are many adenomas in the rectum, we recommend IAA (total colectomy, rectal mucosectomy and ileo-anal anastomosis). 3) Diagnosis and therapy of dysplasia accompanied with the inflammatory bowel disease (ulcerative colitis, tuberculosis, Crohn's disease) remain unclear. There is a deep relationship between cancer and dysplasia and inflammation.