Based on the Rome III criteria (2006), irritable bowel syndrome (IBS) refers to functional bowel disorder in which abdominal pain or discomfort is associated with defecation or a change in bowel habit, and with the features of disordered defecation in terms of stool frequency and consistency. Currently, it is believed that IBS has been a biopsychosocial dysfunction. It means that a biological bowel dysfunction is the final result of brain-gut linkage and modified by the social, environmental and psychological factors. Apart from gut symptoms, IBS patients also have many extra-colonic manifestations, e.g. fibromyalagia, sleep disturbance, headache, dysuria, emotional stress, etc. Thus, IBS per se has a profound impact on living and quality of life of sufferers leading to the excessive social costs for medical seeking behaviour and absenteeism. Among the Asian people, IBS prevalence (5-10%) is comparable to this of western countries.

Basically, the therapeutic objectives for IBS are to improve their functioning in the society. Accordingly, the up-to-date IBS management is to develop a logical strategy including a positive diagnosis, consideration of the patient’s agenda and emotional state, critical appraisal of the efficacies of various drugs and placebo, the use of dietary fibers, continuing care and the graded therapeutic response. Most importantly, a confident diagnosis and enthusiastic explanation of disease pathogenesis and prognosis may decrease over-investigations, excessive visits, costs and medications, and even the uncertainty of consulted patients. Many meta-analyses of therapeutic trials already indicate that the placebo response ranges 40-70%, whereas none of the currently available drugs has been globally effective in treating all IBS symptoms. Perhaps drugs acting as antispasmodics, prokinetics, bulking agents, laxatives, osmotics, antidiarrheals, antidepressants, etc. are optional when consulted subjects exhibit either pain, constipation or diarrhea as their main bowel symptom, respectively. However, a few refractory patients finally need psychiatric consultation and psychotic measures, e.g. hypnotherapy, biofeedback and cognitive behavioural program to improve their annoying symptoms. On the other hand, abnormal visceral perception has been a well-known mechanism leading to IBS. Newly developed drugs acting as agonists or antagonists are now trying to modify the functions of neuro-peptide receptors of enteric (ENS) and central nervous systems. Of them, opioids, somatostatin, neurokinins, chlecystokinin, 5-hydroxytrytamine (5-HT), etc. have been the interested targets to develop new drugs in treating IBS. Unfortunately, none of these drugs are very successfully marketed to treat IBS because their safety remains to be established. Recently, various probiotics have been introduced to treat IBS particularly those of post-infectious type.

In conclusion, IBS treatment is usually tailored to the individual’s symptomatic manifestations ranging from reassurance to psychotherapy. Apart from the traditional medications, new drugs functioning on ENS may be appraisable and considered as the 2nd generation of IBS management in the future.