[The hypersensitive bowel].

The irritable bowel syndrome is above all a syndrome of intestinal pain. Although the intestinal disorders described in this syndrome have prompted several studies focused on intestinal motility, little has been learned from these studies increasing our knowledge on the pathophysiology of this syndrome. The demonstration of colonic hypermotility or various and slightly significant modification in small intestinal motility do not add much to our knowledge. For one, why are clinical signs such as abdominal pain, bowel movement disorders, and abdominal distension, and most likely other motor disorders, found in numerous normal subjects (14 to 30 percent of the normal population) who do not seed medical advice for intestinal signs which are, one must admit, not very alarming? Are patients who complain of functional digestive tract disorders, constantly seeking medical advice and heavy medication consumers, mentally ill (emotional patients, hypochondriacs, depressive, hysterics), are they just under great stress, or do they indeed have chronic pain pathology? A number of studies show clearly that the last hypothesis is most likely true: patients with the irritable bowel syndrome (i.e. hypersensitive bowel) have a chronic pain pathology because their threshold perception of pain is lower than in the normal population. The threshold tolerance to distension of the pelvic colon is lower in these patients than in asymptomatic patients. The gastric transmural potential is lower in patients complaining of functional intestinal disorders, and it is known that a fragile mucosa is highly sensitive to normally innocuous stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)