Carbohydrate malabsorption is minimal in school-age cystic fibrosis children.

Fifteen school-age cystic fibrosis children, participating in a year-long nutritional management study, were hospitalized at six-month intervals for balance studies during which they continued "free-choice" diets and their usual enzyme supplementation. Stools were analyzed for fat and protein by conventional methods and for carbohydrate using a recently validated anthrone method. Despite persistent fat and protein malabsorption, less than 1% of ingested carbohydrate was lost intact in the stools. Comparison of baseline and placebo balance studies showed fecal excretion of carbohydrate to be independent of intake, in contrast to the fat and protein results. Using a thin-layer chromatography method capable of detecting microgram quantities of urinary organic acids, no short-chain fatty acids were detected in the stool. Further exploration of carbohydrate as a dietary energy source for this patient group with increased energy demands should be pursued.