12C-glycocholate test in Crohn's disease its value in assessment and treatment

Abstract

The ¹⁴C-glycocholic acid test (¹⁴C-GCA) has been assessed in 27 patients who have had resection of the ileum and colon for Crohn's disease and in 19 patients with unoperated stable Crohn's disease. The incidence of increased breath output of ¹⁴CO₂ and faecal output of ¹⁴C was significantly greater in operated patients. Half the unoperated patients had normal results and, of the others, a modest increase in faecal ¹⁴C was the usual finding. There was no correlation between the ¹⁴C-GCA test, the Schilling test, and the extent and severity of the radiological signs in the unoperated patients. Metronidazole therapy was poorly tolerated and had little or no influence on symptoms but did decrease the excretion of ¹⁴CO₂ in the breath when the ¹⁴C-GCA test was repeated. Cholestyramine therapy was beneficial in the majority of resected patients with diarrhoea and an increased faecal ¹⁴C excretion and, on repeat testing, there was a significant increase in the output of breath ¹⁴CO₂. The beneficial effect was less marked in the unoperated patients and the breath ¹⁴CO₂ output remained normal in those retested. Interruption of the enterohepatic circulation of bile acids did not seem to make an important contribution to the symptoms of patients with stable unoperated (and uncomplicated) Crohn's disease, even when the ileum was extensively involved.