[How to find the cause of a chronic adult diarrhea].

Chronic diarrhea can be defined as the passage of more than 3 loose stools per day during more than 4 weeks. Differential diagnosis include fecal incontinence (stool consistency is normal), rectal syndrome (passage of blood and mucus but no liquid or loose stools) and fecal impaction. The proposed guidelines are based upon a classification of chronic diarrhea that distinguishes colonic, small bowel, pancreatic, endocrine and miscellaneous causes of chronic diarrhea. It also takes into account the frequency of the many causes of chronic diarrhea. One of its main objectives is to ensure the proper diagnosis of severe causes of chronic diarrhea, notably colorectal neoplasia.