Several methods have been developed to identify the disorder but there are difficulties with all of them. Diagnosis of<unk>  is easily and reliably made by the SeHCAT test. This nuclear medicine test involves two scans a week apart and so measures multiple cycles of<unk> <unk>  excretion and reabsorption. There is limited radiation exposure (0.3 mSv). Retention of SeHCAT at 7 days is normally above 15%; values less than 15%, 10% and 5% predict respectively mild, moderate and severe abnormal retention and an increasing likelihood of response to<unk> <unk>  sequestrants. This test is not licensed in the USA, and is underutilized even where it is available. Older methods such as the 14C-glycocholic breath test are no longer in routine clinical use. Measurement of 7α-Hydroxy-4-cholesten-3-one, (C4), a<unk> <unk>  precursor, in serum, shows the increased<unk> <unk>  synthesis found in<unk> . This test is an alternative diagnostic means when available. Fasting blood FGF19 values may have value in the recognition of the disease and prediction of response. The various biomarkers give similar diagnostic yields of around 25% in patients with functional bowel disorders with diarrhea. In countries such as the USA, where SeHCAT is not available, fecal<unk> <unk> s and C4 are available to make the diagnosis. Classification<unk>  was first recognized in patients with ileal disease. When other causes were recognized, and an idiopathic, primary form described, a classification into three types was proposed: * Type 1:<unk> , secondary to ileal resection, or ileal inflammation (e.g. in Crohn's disease) * Type 2: Idiopathic<unk> , Primary<unk> <unk>  diarrhea * Type 3: Secondary to various gastrointestinal diseases including cholecystectomy, vagotomy, small intestinal bacterial overgrowth, radiation enteropathy, celiac disease, chronic pancreatitis, etc.
Bile acid malabsorption
Irritable bowel syndrome
Fructose malabsorption
Microscopic colitis
Glucose-galactose malabsorption
Exocrine pancreatic insufficiency
Sucrose intolerance
Lactose intolerance