The treatment approach in patients with IBS is usually guided by the predominant symptoms (ie, pain, diarrhea, or constipation) as well as the severity of the disorder.

Most patients with IBS have mild and infrequent symptoms with no, or only little, associated disability. These patients do not usually need antidepressants. Reassurance, education, recommendations for dietary changes, and short-term symptomatic treatment are sufficient in most of these cases. Patients who have moderate or severe symptoms that considerably affect their daily activities and quality of life may require additional pharmacologic treatments, including psychopharmacologic (eg, antidepressants) and/or psychological and behavioral therapies.^[1]

The rationale for the use of antidepressants in IBS is the coexistence of psychological disturbances, particularly in patients with more severe symptoms who seek medical care, and their effect/action on reducing gut sensation. The latter neuromodulatory analgesic effect of these agents is unrelated to their psychotropic effects. Thus, antidepressants can be used in IBS patients with or without psychiatric comorbidity (eg, depression, anxiety).

A recent meta-analysis of 12 studies concluded that antidepressants are effective in IBS patients. On average, 3.2 patients need to be treated to achieve 1 positive response in a patient's symptoms.^[2] Tricyclic antidepressants have been best studied in IBS patients with pain and diarrhea. Low doses of desipramine (50-100 mg) or amitriptyline (25-75 mg) appear to be effective in controlling IBS symptoms in these patients. Although data on SSRIs are still limited, the current information suggests a beneficial effect. SSRIs may be preferred in older patients or in those with constipation because they have little or no anticholinergic effects.^[1]

Long-term adverse effects are common with antidepressant treatment and relate to the anticholinergic, serotonergic, sedative antihistaminic, and alpha-adrenergic effects. These effects must be considered in choosing the treatment approach. In addition, because psychotropic agents also affect intestinal motility,^[3] the patient's bowel function should also be considered when selecting an antidepressant medication.

Finally, because the disorder is multidetermined, it is important to view medication therapy as part of a more comprehensive management plan in the setting of IBS.^[4]