Functional digestive disorders – pathophysiological approach

In contrast to organic diseases due to structural lesions or humoral aberrations, functional disorders have been ascribed to abnormal functions. But which functions? The term Functional Digestive (or Gastrointestinal) Disorders was introduced after discovery of tests of gastric secretion at the end of the 19th century when digestive symptoms were ascribed to abnormal gastric acidity. The diagnoses hyperacid or anacid dyspepsia became popular and correction of acidity by antacids or hydrochloric acid was a seemingly logical therapy. However, further studies showed that gastric acidity plays little if any role in producing digestive symptoms and the above-mentioned terms turned out to be obsolete. At present the pathogenic potential of gastric acid is limited to “acid related diseases” – peptic ulcer and gastrooesophageal reflux disease, the pathophysiology of symptoms of “functional disorders” has switched to disturbances of motility. The credit for stressing the importance of motility for producing digestive symptoms goes to W.C. Alvarez, author of the terms intestinal polarity and motor and metabolic gradient [2]. Disturbance of these functions which this author called reversed peristalsis was considered to be an explanation of symptoms such as belching, regurgitation, halitosis, anorexia, nausea, vomiting, bloating and constipation [1]. In the 20th century disturbances of gastrointestinal motility attracted major attention in gastroenterological research and were supported by radiologic, manometric, sonographic, isotopic and other tests which yielded a wealth of objective data and findings. Disturbances of motility – tonus, peristalsis, propulsion, transit, evacuation – have been identified as pathophysiological explanation of some symptoms, however, these were inconsistent or absent in others. A comprehensive classification based on motility disorders was found to be impossible. In 1980 an international consensus was initiated in this topic and later on the ROME Criteria I, II, and III were published [5–7] in which functional disorders were classified according to the clinical symptomatology. A Czech system of functional digestive disorders was published in 1964 [12] and LEADING ARTICLE/ ÚVODNÍK