Increased sensitivity of the cholylglycine breath test for detecting ileal dysfunction

Deconjugation of bile salts was assessed by measuring the rate of appearance of 14-CO2 in the breath after the administration of cholyl [1-14-C]glycine to patients with ileal dysfunction (ileitis or ileal resection), cholesterol cholelithiasis with or without cholecystectomy, and control subjects (healthy or with diarrhea). Vitamin B12 absorption was also measured in many of the patients with ileal dysfunction by determining the recovery of 57-Co in the urine (Schilling test). The percentage of administered 14-C excreted in breath 14-CO2 was increased in the patients with ileal dysfunction, but there was considerable overlap between the patients with ileal dysfunction and the control subjects. Breath 14-CO2 was excreted more rapidly in all the patients with ileal dysfunction than in the control subjects. Of the calculated 24-hr breath excretion 78.3 plus or minus 8.9% SD of administered 14-C was excreted in 12 hr in the patients with ileal dysfunction, compared to 39.1 plus or minus 13.1% in the control subjects; only 1 of the 19 patients with ileal dysfunction overlapped with the control subjects. The Schilling test was normal orequivocal in 5 of 14 patients with ileal dysfunction. The percentage of administered 14-C excreted in breath 14-CO2 was increased in patients with cholecystectomy, but excretion was not more rapid than in the control subjects. The data suggest that the sensitivity of the breath test for diagnosing ileal dysfunction may be usefully increased by determining the rate of excretion of breath 14CO2.