ABSTRACT. Several factors play a role in the cause of malabsorption in CF. Besides the enzyme deficiency in the secretion of the exocrine pancreas, decreased bile‐salt concentration in the gut may also be an important factor in the fat malabsorption. The contribution to the fat absorption by other lipases, such as lingual lipase and gastric lipase, remains to he proved. The therapeutic measures are only partly effective because of the breakdown of swalled enzymes by gastric acid. Some improvement is reached by using a new acid‐resistant coating for the enzyme supplement. Newly developed and essential for its success is the application of small coated particles to prevent retention in the stomach, and the easy breakdown of the coating in an alkaline solution. The treatment of the bile salt deficiency has not been successful until now. A trial with additional Tween 80, with the option of supplementing the detergent activity which was found to he successful in Crohn disease, was without marked success. Copyright