胆汁酸
The SeHCAT test is used to investigate patients with suspected bile acid malabsorption, who usually experience chronic diarrhea, often passing watery feces 5 to 10 times each day. When ileum has been removed following surgery, or is inflamed in Crohn's disease, the 7-day SeHCAT retention usually is abnormal, and most of these patients will benefit from treatment with bile acid sequestrants. The enterohepatic circulation of bile acids is reduced in these patients with ileal abnormalities and, as the normal bile acid retention exceeds 95%, only a small degree of change is needed. Bile acid malabsorption can also be secondary to cholecystectomy, vagotomy and other disorders affecting intestinal motility or digestion such as radiation enteritis, celiac disease, and small intestinal bacterial overgrowth.