Bile acids and their role in functional gastrointestinal disorders

Studies of the role of bile acids have been conducted for many years. Thanks to constantly improving research methods, the systemic action of bile acids has been evaluated with increasing precision. It is now believed that disturbances in the synthesis, transformation and transport of bile acids may be one of the causes of functional bowel disorders. Constant renewal of the bile acid pool and secretion of bile acids into the gastrointestinal lumen is regulated by feedback loops. Bile acids play the role of signaling molecules by binding to the appropriate receptors and influencing the synthesis of other signaling molecules at the cellular level. Disturbances of synthesis, reabsorption and changes in the proportion of bile acids all lead to motor dysfunction and intestinal secretion. The most common symptoms are diarrhea, constipation or irritable bowel syndrome. This article discusses the basic issues of the synthesis and circulation of bile acids. On the basis of in vitro and in vivo findings, an outline of the regulation of physiological processes and the pathophysiology of diarrhea and constipation in the context of bile acids is presented. Understanding the role of bile acids in the pathophysiology of functional intestinal diseases creates new therapeutic options for patients suffering from functional diarrhea or constipation.