Relation of thickening of colon wall to pancreatic-enzyme treatment in cystic fibrosis

Fibrotic strictures of the colon in association with colon-wall thickening on abdominal ultrasound have been described in children with cystic fibrosis. We determined the prevalence of colon-wall thickening in 99 children with cystic fibrosis (aged 6 months to 17 years, 45 male) and 38 healthy controls (aged 1 month to 39 years, 21 male). In controls, peristalsis was uniformly rapid and maximum wall thickness of the fully relaxed colon was 0·8 mm (median 0·6 mm). 24% of the patients had a colon-wall thickness of 1·5 mm or more (maximum 3·4 mm); 48% of children on high-strength pancreatin receiving more than 265 units/kg per day of protease had thickening of more than 1·5 mm compared with less than 12% of children on any other dose. Children on high-strength pancreatin were 5·2 (95% Cl 1·2-21) times more likely to have colon-wall thickness of 1·5 mm or more than children taking less than 265 units/kg per day of protease in a standard-strength preparation. This risk rose to 10 (2·5-39) times more likely if laxatives were taken with a high-strength preparation. Lipase or amylase intake, age, sex, genotype, and other medical or drug history were not significantly associated with colon-wall thickening. 1 child required a hemicolectomy for bowel obstruction and another developed haemorrhagic colitis. In 17 children, 2 months after stopping high-strength, high protease, preparations and efforts to reduce enzyme intake, colon-wall thickness had regressed from a median 2·0 mm (range 1·0-3·4) to 1·8 mm (0·9-2·7) (p=0·005). The use of high-strength pancreatin preparations in conjunction with a high protease intake probably causes thickening of the wall of the colon.