Significance of duodenal disaccharidases. A comparative study of duodenal and jejunal values.

Endoscopic biopsies at the inferior duodenal flexure from 36 patients were assayed for disaccharidases. Comparative studies in 8 patients were carried out from this location and from the duodenojejunal flexure. 16 patients with lactase values under 20 U/g protein and normal histology also underwent a lactose tolerance test. Evidence is presented that the easily performed duodenal biopsies give the same information as those from the angle of Treitz, at a level about 40% under the latter. Tolerance to lactose was in close relation with the lactase level in 16 patients, the limit being at about 5 U/g protein.