New Therapies in Irritable Bowel Syndrome: What Works and When

Orla Craig


Curr Opin Gastroenterol. 2018;34(1):50-56. 

In This Article


For those failing first-line treatments, consideration should be given to antidepressants. The rationale for using antidepressants in functional gastrointestinal disorders is that they modulate pain perception and may treat coexistent psychiatric illness.[40] They can cause constipation or diarrhoea as a side effect, which may be beneficial in the treatment of an abnormal bowel pattern associated with IBS. A systematic review and meta-analysis of almost 1100 patients demonstrated that both tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) are effective treatments for IBS with an NNT of 4.[41] In the psychiatric setting TCAs are generally used at dosages of 200–300 mg, however, they have pain-modulating effects at much lower dosages.[42] A starting dose of 5–10 mg of amitriptyline is generally recommended; they are useful, in particular, for those in whom abdominal pain is problematic.[43] TCAs prolong orocaecal and whole-gut transit both in healthy controls and patients with IBS,[44] and therefore, are useful in the management of IBS-D. Tertiary amine TCAs such as Amitriptyline and Imipramine are frequently poorly tolerated because of their anticholinergic and antihistaminic side effects. Secondary amine TCAs, Nortriptyline and Desipramine have less activity at these receptors and may be better tolerated.[42] SSRIs do not have significant analgesic effects but nonetheless have been found to be effective in treating overall symptoms of IBS.[41] They can be considered in IBS where TCAs fail.[43] In contrast to TCAs, SSRIs have been shown to accelerate gut transit[45] and, therefore, are more useful in the management of IBS-C.