Ileal dysfunction and bacterial overgrowth in patients with Crohn's disease

The intestinal bile acid metabolism was studied in sixty-one patients with non-operated Crohn's disease (twenty-seven ileitis and thirty-four ileocolitis patients) by means of the 14C-glycocholate breath test with marker-corrected faecal analysis before and after a short course of antibiotics. The results of the combined breath and faecal analysis were compared with the data of other tests detecting bacterial overgrowth and ileal dysfunction. Fifteen of the sixty-one patients (25%) presented with a 14C excretion pattern consistent with bacterial overgrowth of the small bowel. Repetition of the combined breath and faecal analysis after antibiotic treatment revealed that concurrent ileal dysfunction was present in at least six of these fifteen patients. In twenty other patients elevated marker-corrected 14C faecal excretion indicated ileal dysfunction. Thus, the overall incidence of ileal dysfunction amounted to 26/61 (44%). The sensitivity of the bile acid breath test with marker-corrected stool analysis was comparable to that of aerobic and anaerobic jejunal cultures in twenty non-selected patients for the detection of bacterial overgrowth, and to that of chemical bile acid measurement in stools for the detection of ileal dysfunction. The bile acid breath test with faecal analysis was more sensitive than measurement of glycine-taurine ratio in bile (twenty patients) and the Schilling test.