Melanosis coli or mucosa ischemia? A case report.

The presence of a black or brown stoma may indicate a serious problem, such as a necrotic stoma, or may be the result of a benign pigmentation disorder known as melanosis coli. Melanosis coli is caused by anthraquinone laxative abuse and has no associated morbidity. The case report involves a 63 year old white female admitted to the hospital emergency room. Secondary to uterine choriocarcinoma, an end sigmoid colostomy was created. The mucosa was moist but black, despite the fact that the serosa had been pink and bled easily. Biopsy revealed neither necrotic stoma nor infarcted bowel but melanosis coli related to the patient's 20 year history of laxative use for chronic constipation. Melanosis coli does not require medical or surgical intervention and is considered a benign pigmentation disorder. However, knowledge of this condition and of the bowel patterns and habits of patients prior to their ostomy surgery, is essential to establishing the differential diagnosis for a brown or black stoma.