[Epidemiology of the irritable bowel syndrome]. / Epidémiologie du syndrome de l'intestin irritable.

Based on recent epidemiologic studies of functional intestinal disorders, we have attempted to answer the following two questions: a) what is the prevalence of functional intestinal disorder in the Western world, b) are there epidemiologic variations in the different modes of symptomatic presentation of functional intestinal disorders? The overall prevalence of functional intestinal disorders in the Western world ranges between 17 and 23 percent according to the country considered, and is between 14 and 18 percent for the irritable bowel syndrome and 4 to 8 percent for painless constipation. The "irritable intestine" group is characterized by a sex ratio of close to one, a median age near 40, a strong influence of stress on symptoms, and the frequency of complaints such as nausea, vomiting, migraine, and pyrosis. The syndrome is seen in active subjects, who believe that they are "sick", and as such, seek medical advice often. Anxiety and depression are frequently encountered. Patients are often athletes, smokers, and have diarrhea. On the other hand, "painless constipation" is characterized by a high prevalence of women and age over 50. Often these subjects do not have any active professional activity. Stress-related and extradigestive symptoms are rare. They do not consider themselves "sick" and do not seek medical advice very often. Conversely, they use laxatives frequently. Individualization of epidemiologically different groups suggests that the pathophysiology may differ between the two groups and perhaps that there are specific therapeutic and diagnostic approaches accordingly.

[Epidemiology of intestinal functional disorders in an apparently healthy population]. / Epidémiologie des troubles fonctionnels intestinaux dans une population apparemment saine.

The characteristics and the prevalence of functional bowel disorders in the general French population are unknown. Based on an epidemiological inquiry in a random population of 1,200 persons who were not seeking care, residents in our country we established: the prevalence of symptoms suggestive of functional bowel disorders; the epidemiological differences between symptomatic subgroups which included abdominal pain with or without bowel dysfunction, diarrhea and constipation. The amount of cases and the prevalence in each subgroup were: abdominal pain, 165, 13.8 p. 100, painless constipation, 75, 6.3 p. 100, diarrhea, 10, 0.8 p. 100. As a whole, functional bowel disorders occurred in 20 p. 100 of our population. The "irritable bowel syndrome" group defined as abdominal pain and/or diarrhea differ from normal subjects by the following higher frequency of age under 50, subjects in active duty, antecedents of diverticulosis, influence of stress on symptoms, nausea, vomiting, migraines, pyrosis and number of visits to a doctor. However neither the sex-ratio nor professional occupation were relevant. The constipation group differed from normal because of the higher frequency of female sex, antecedents of hiatus hernia, use of laxatives but not because of age nor by the number of associated symptoms. In conclusion, functional bowel disorders occurred in 20 p. 100 of our population; two subgroups were clearly different from an epidemiological point of view, the irritable bowel syndrome (13 p. 100) and constipation (7 p. 100); therefore these two groups deserve a specific physiopathological, psychological and therapeutic approach.