In the randomised controlled trial reported in this issue of Gut, Tack and colleagues¹ compared citalopram and placebo in 23 patients with irritable bowel syndrome (IBS) over a six week initial treatment period using a parallel group design (see page 1095). The dose of citalopram was similar to that used in the treatment of depressive disorders but any patients with depressive disorder were excluded from this trial. The results showed that citalopram was superior to placebo in terms of the primary outcome measure—days with abdominal pain—and this improvement was unrelated to change in mood, change in stool pattern, or the effect of intravenous citalopram on rectal distension thresholds.

Overall this was not a good trial. The total number of outcome measures exceeded the number of subjects in the trial. The crossover part of the trial was discounted because symptoms did not return to baseline values after the first treatment period. It is not at all clear how the patients were selected and, therefore, whether the results might be generalised to clinic populations. Strengths of the study however include the high participation rate throughout the trial and the combined diary and questionnaire measurements.

In spite of the weaknesses of the trial design, this report is interesting because of the paucity of randomised placebo controlled trials of selective serotonin reuptake inhibitor (SSRI) antidepressants in IBS.^2,3 In one trial of patients who had failed to respond to a high fibre diet, Tabas et al found that a low dose of paroxetine was superior to placebo in terms of overall …