Chronic diarrhoea is common and mostly due to diarrhoea predominant irritable bowel syndrome (IBS-D). IBS-D affects about 11% of the population, however up to a third of these patients actually have bile acid diarrhoea (BAD). There are, therefore, more than one million sufferers of BAD in the UK. BAD is caused by small bowel malabsorption of bile acids and the increased bile acids in the large intestine cause diarrhoea. Once diagnosed, the treatment of BAD is simple and effective. BAD, however, is often not diagnosed because of a lack of easily available and reliable diagnostic methods. In the United Kingdom, the radiolabelled 23-seleno-25-homotaurocholic acid test (SeHCAT) is the gold-standard method of diagnosis. SeHCAT, however, is expensive, inconvenient to the patient, involves radiation exposure and has limited availability. As such, a laboratory biomarker is desirable. This review briefly discusses the pathophysiology and management of BAD and critically evaluates methods for its diagnosis, including serum 7α-hydroxy-4-cholesten-3-one, faecal bile acid measurement, serum fibroblast growth factor 19, urine-2-propanol, and the 14C-glycocholate breath and stool test.

慢性腹泻很常见，主要是由于腹泻为主的肠易激综合征（IBS-D）。IBS-D影响了约11％的人口，但是这些患者中有多达三分之一实际上患有胆汁酸腹泻（BAD）。因此，英国有超过一百万的BAD患者。BAD是由于小肠对胆汁酸的吸收不良所致，大肠中胆汁酸的增加引起腹泻。一旦被诊断，BAD的治疗是简单有效的。然而，由于缺乏容易获得和可靠的诊断方法，常常无法诊断出BAD。在英国，放射性标记的23-硒基25-高尿酸胆酸测试（SeHCAT）是诊断的金标准方法。然而，SeHCAT价格昂贵，给患者带来不便，涉及辐射暴露并且可用性有限。因此，实验室生物标记是可取的。这篇评论简要讨论了BAD的病理生理和管理，并严格评估其诊断方法，包括血清7α-羟基-4-胆甾烯3一，粪便胆汁酸测量，血清成纤维细胞生长因子19，尿液2-丙醇，以及14C-甘醇胆酸的呼气和大便测试。