Chronische Diarrhoe - Fallgrube Laktasemangel

b Gastroenterologie und Hepatologie UniversitätsSpital Zürich Summary Chronic diarrhoea - the lactase deficiency trap We report the case of a 78-year-old patient with chronic diarrhoea who was diagnosed with lactose intolerance by lactose intolerance quick test (biopsy ma- terial) and genetic testing for primary lactose malabsorption. She was labelled non-compliant when the diarrhoea failed to improve under a lactose free diet. Extended work-up revealed a VIPoma in the pancreas and the patient improved under treatment with octreotide. This case is an example of how correct diag- nosis is delayed when excessive value is attached to "hard evidence" (i.e. biopsy and genetic testing) over clinical commonsense. Lactose intolerance is a clinical diagnosis. Lactose intolerance quick test and CT 13910 genotyping are new tests for identification of lactase deficiency. Accordingly, if lactase defi- cient patients fail to improve on a lactose free diet, another diagnosis must be considered.