[Milk intolerance, lactose intolerance and lactase deficiency in partial resection of the stomach].

Of 40 patients with a partial gastrectomy (Billroth-II) 10 developed a milk intolerance and 11 had a lactase deficiency, the latter in 4 cases appearing together with a decrease in other disaccharidases. Only 2 of the 11 lactase-deficient patients complained of milk intolerance. The Ethanol lactose tolerance test (ELTT) was performed in 21 patients and was found to be abnormal in 6. Whereas cases of abnormal ELTT usually (4 of 6 cases) showed a lactase deficiency, only 2 patients with milk intolerance showed an abnormal ELTT and lactase deficiency. Milk intolerance can therefore only exceptionally be explained by lactase deficiency, and lack of lactase in the upper jejunum usually does not produce intolerance symptoms. Moreover, in comparable determinations from the afferent and efferent jejunal loop no differences in enzyme activities could be observed.