Curbside Consultation of the Colon: 49 Clinical Questions

Brooks D. Cash, MD, FACP, CDR, MC, USN

Question 12: What Should I Suspect When I See Melanosis Coli And What Is Its Clinical Relevance? (continued)

Erica Roberson, MD; Arnold Wald, MD

Melanosis coli is a dark brown-black discoloration of the colonic mucosa most often seen with exposure to anthraquinone laxatives (Figure 12-1). It is usually more prominent in the proximal colon and cecum, although it can affect the entire large bowel. Up to 70% of patients who use anthraquinone laxatives chronically will develop melanosis coli within 4 to 12 months of starting the drug. It is therefore often seen in women aged 20 to 70 (the population most often affected with constipation), but its development does not depend on age or duration of constipation. Anthraquinone laxatives…