they may also offer relief for transient deficiencies such as may occur with small bowel injury.The strengths of these data lie in the large sample size that is nationally representative and the consistent and experienced personnel who performed the analyses; the enzyme assay has been in use and has not changed in decades. The weaknesses of these data lie in the lack of clinical correlation, the selection by the endoscopists of a young age group from which samples were obtained, the inability to control for sample integrity throughout the entire process of obtaining the samples, and handling and shipping. The analyses were performed manually, and human error is always a possibility. We conclude that the most common disaccharidase deficiency is lactase followed by pandisaccharidase. Sucrase deficiency was rare in these samples.