Pharmacological treatment of the irritable bowel syndrome and other functional bowel disorders

Functional digestive disorders constitute one of the main causes of consultation in gastroenterology and primary health care. Is still unclear whether therapy has to be aimed to the gut, to the neural pathways controlling bowel motility and perception, or to the processing mechanisms of symptoms and disease behaviour. It is conceivable that in the next future better understanding of functional bowel disorders pathophysiology will help us to tailor treatment for different patients. At the moment, subclassification of the diverse patterns of symptomatology allows to adjust new treatments for irritable bowel syndrome (IBS) according to the clinical predominance for each patient. The knowledge of motor and sensorial response to different stimuli in IBS patients and the pathways to the central nervous system is an important source of information for the development of new molecules. Fiber-enriched diet is frequently given for constipation-predominant IBS. Loperamide, antispasmodic drugs and tricyclic antidepressants are nowadays the basis for pharmacological treatment of diarrhea- predominant IBS. The scientific evidence supporting this therapeutical approach is however limited. Visceral analgesics and serotonin agonists and antagonists may play an important therapeutical role in the near future. However, it is not likely that one single treatment will help every functional bowel disorder patient and many of them will need a more complex approach with a multidisciplinary therapy (diet, psychotherapy, medications).