Melanosis coli in inflammatory bowel disease.

Melanosis coli is a relatively common condition in which pigment is deposited in macrophages in the colonic lamina propria. The association with anthraquinone laxatives is well described, but melanosis coli has also been described in patients not using these agents. We report 25 patients with inflammatory bowel disease and melanosis coli, 5 (20%) of whom had documented laxative use. Most patients had ulcerative colitis (72%) or Crohn's colitis (24%), and the mean duration of inflammatory bowel disease was more than 7 years. These data raise the possibility that chronic colitis could cause melanosis coli even in the absence of laxative use.