[Villous rectal adenomas and secretory diarrhea]

Hypersecretion following villous adenomatosis of the rectum is demonstrated by two single case studies. Both patients exhibited a secretory diarrhea with a 2.000-2.500 and 1.000 ml daily stool volume respectively, resulting in severe and life-threatening (first patient) loss of water and electrolytes. With increasing stool volume, rising concentrations of Na and Cl were observed in the stool and approached plasma levels. Consecutively the potassium concentration decreased to values between 15 and 23.4 mmol/l in the first severe case and to 28 and 31 mmol/l in the patient with the lowest stool volume. Elevated PG-E2 concentrations in the fluid moiety of the stool (up to 13.3 ng/ml and 0.98 ng/ml respectively) as well as the response to treatment with Indomethacin support the idea of a PG-E2 induced pathological loss of water and electrolytes. While 100 mg Indomethacin/day led to cessation of symptoms in the less severe case, even 400 mg Indomethacin/day were not able to reduce the massive rectal water loss in the first most severe patient to less than 1,000 ml/day. Surgical removal of villous adenoma showing hypersecretory activity is the only promising therapy. In case of inoperability, denial of surgical intervention or just for palliative treatment prior to surgery we recommend the inhibition of PG-synthesis with Indomethacin.