[Measurable parameters in the irritable bowel syndrome (author's transl)].

In patients suffering from the irritable bowel syndrome no morphological substrate for this disease can be found; thus quantitation of functional parameters might be desirable. In the colon these patients exhibit myoelectrical waves of increased frequency, e.g. 3 per minute, as well as an exaggerated retropulsion and a prolonged motor response after food intake, indicating an abnormal motility pattern. In the small gut transit is either accelerated, causing diarrhea, or slowed down, causing constipation; in addition, there is an increased retrograde movement of intestinal gas. The pain threshold is decreased in the small and large bowel; inflation of a balloon or insufflation of gas may reproduce the clinical symptoms of the patients. In the terminal ileum there is net fluid secretion instead of net absorption, as normal. Even the esophagus may be affected, since manometry has demonstrated disturbed peristalsis and a reduced pressure of the lower esophageal sphincter. Such quantification of intestinal function is not a substitute for careful clinical work-up. It has however contributed to a better understanding of the underlying functional disturbances in irritable bowel syndrome.