[Role of acid in functional dyspepsia].

Recently, the Japanese Society of Gastroenterology (JSGE) developed an evidence-based clinical guideline for functional dyspepsia (FD). Multiple factors (including disturbance of gastric motility and hypersensitivity) may be associated with the pathophysiology of FD. Among these, acid plays a crucial role in the pathogenesis of FD. The presence of gastric acid affects gastric motility and sensitivity. Additionally, duodenal acidification induces proximal gastric relaxation and hypersensitivity to gastric distension. Systematic review showed that proton pump inhibitors (PPIs) and histamine type -2 receptor antagonists (H2RAs) are effective for the treatment of FD as the first line therapy, and both provide same level efficacy.