We read with great interest the article by Tack et al on the effect of the selective serotonin reuptake inhibitor (SSRI) citalopram on symptoms in patients with irritable bowel syndrome (IBS) (Gut 2006;55:1095–103). The usefulness of the results of this study are however debatable. Several previous studies have investigated the effect of tricyclic antidepressants and SSRIs on functional gastrointestinal symptoms. Because of errors or lack of clarity in study design, inclusion of very selected patient populations and, above all, small sample sizes, their role in the treatment of patients with IBS in daily clinical practice remains unclear.

The study of Tack et al, as already correctly pointed out by Creed in his commentary (Gut 2006;55:1065–7), also suffers from major shortcomings in study design, poor description of study population and no information on whether or not subjects and physicians/investigators were blinded and, if yes, how.

Nevertheless, Creed claims that this study provides useful information on the effect of citalopram on the primary outcome measure—number of days per week with abdominal pain. What is relevant for patients as well as physicians is the risk of reduction in the number of days with abdominal pain after citalopram treatment. From the results of this study a relative risk of abdominal pain can be …