Visual diagnosis: Chronic diarrhea and failure to thrive in a 5-year-old girl.

Chronic GVHD usually develops 100 days after BMT and is a serious and potentially life-threatening long-term complication. Chronic GVHD can occur after previous or ongoing acute GVHD or in patients without a history of acute GVHD (eg, de novo disease) as illustrated by this case. In evaluating a patient presenting with chronic diarrhea more than 100 days after BMT, one must consider a serious underlying illness such as chronic GVHD because it is a major cause of morbidity and mortality of allogeneic stem cell transplantation. As indicated by this case, chronic GVHD can cause diarrhea. Complete evaluation of the diarrhea state should be part of the initial investigation. In many cases, however, the diagnosis of GVHD is not straightforward, and gastrointestinal biopsy and histologic confirmation is often necessary to corroborate a clinical impression of chronic GVHD.