Chronic diarrhea and melanosis coli caused by wellness drink.

Dear Editor: The development of melanosis coli due to anthraquinonecontaining laxatives is well established. Melanosis coli is an unspecific pigmentation of the colonic mucosa that can sometimes be detected by endoscopy, but is more often revealed by histology only. The pigmentation is caused by apoptotic cells which are ingested by macrophages and subsequently transported into the lamina propria, where lysosomes use them to produce lipofuscin pigment, not melanin as the name suggests. Some authors therefore prefer the expression “pseudomelanosis coli”. It is mostly reversible after withdrawal of the anthraquinone. Although there is no convincing evidence for chronic use of anthraquinone-containing laxatives to be a risk factor for colorectal neoplasia or colonic nerval degeneration in humans, severe adverse effects have been reported for these drugs. Here, we report a case of chronic diarrhea in which the histopathologic finding of melanosis coli lead to anthraquinones which were consumed as general wellness medication. A 76-year-old male patient of Russian origin was referred to our hospital with chronic diarrhea of 6 months duration. He reported six to eight watery bowels per day which also occurred at night. Further symptoms were abdominal pain before defecation and meteorism. He denied weight loss, fever, night sweats, or vomiting. Preexisting medical conditions included a Billroth II operation for duodenal ulcer disease, arterial hypertension, cataract, and ischemic stroke with minor residua. At the time of admission, the patient was regularly taking aspirin and metoprolole. Lactose intolerance had been diagnosed earlier but diarrhea continued under a lactose-free diet. He had been a smoker of 50 pack years until 5 years prior. On admission, he was afebrile with a heart rate of 74 and blood pressure of 165/85. Physical examination was unremarkable, the abdomen showed no tenderness or other pathological findings. Laboratory data for sodium, potassium, CRP, white blood cell count, pancreasand liverenzymes were normal. Minimal anemia was present (hemoglobin 13.4 g/dl, normal 14–18). Apart from reduced vitamin B12 (152 ng/l, normal 310–1,100) laboratory values did not indicate malabsorption: iron, calcium, vitamin D, and folic acid were normal. Stool specimens for bacterial and parasitic agents where unremarkable. Abdominal ultrasound showed no abnormal findings apart from mild hepatic steatosis. Duodenal biopsy did not yield evidence of Whipple’s or celiac disease. A colonoscopy was performed, showing diverticulosis, two erosions in the Int J Colorectal Dis (2009) 24:595–596 DOI 10.1007/s00384-008-0625-7