Dilutional diarrhoea: under-diagnosed and over-investigated

We report two cases of factitious diarrhoea caused by stool dilution, In th e first report stools from a patient with chronic diarrhoea were found to h ave been diluted with urine, and the diarrhoea further compounded by surrep titious laxative misuse, In the second report, after prolonged investigatio n of high output ileostomy, the patient's ileal effluent was found to have been diluted with water. We conclude that factitious diarrhoea, in particul ar dilutional diarrhoea, is over-investigated and underdiagnosed, Stool wei ghts, complete input/output measurement, analysis of stool osmolality and e lectrolytes, and laxative screening are essential in the investigation of c hronic watery diarrhoea, (C) 2000 Lippincott Williams & Wilkins.