Abstract
Electron microscopy was used to measure microvillous surface area in seven small intestinal biopsies showing secondary disaccharidase deficiency and in five biopsies having normal disaccharidase levels. There were significant reductions in microvillous surface area in the enzyme deficient group, although the microvilli were not severely damaged. Histological abnormality was not always present with disaccharidase deficiency. There was no significant difference in intraepithelial lymphocyte counts between the two groups.