Small bowel biopsy for disaccharidase levels: evidence that endoscopic forceps biopsy can replace the Crosby capsule.

Lactase, sucrase and maltase activities in endoscopic biopsies from the second part of the duodenum were compared to those in Crosby capsule biopsies from the proximal jejunum. In patients with villous atrophy disaccharidase activities were reduced compared with histologically normal mucosa in the duodenum and jejunum. Disaccharidase activities were significantly lower in the duodenum than in the proximal jejunum of patients with histologically normal mucosa and in those with partial villous atrophy but not significantly different for total villous atrophy patients. Primary and secondary disaccharidase deficiencies can be identified in biopsies from the duodenum. Duodenal biopsy is a valid alternative to jejunal biopsy for the diagnosis of disaccharidase deficiency.