[Melanosis coli(author's transl)].

Melanosis coli is caused by deposits of malanin- or lipofuscin-containing pigments in the colon mucosa; it is a conspicuous sign of long standing abuse of anthrachinonic laxatives. Melanosis coli can be easily diagnosed during rectoscopy, using morphological as well as histological criteria; nevertheless this condition is often overlooked or goes unnoticed. Abuse of laxatives, which is denied or concealed rather often by patients, does however explain in many cases otherwise unexplained abdominal complaints. Four cases are reported demonstrating the diagnostic significance of colonic melanosis.