Table 3. Studies that discuss the effect of pharmacological treatment on IBS.

IBS: irritable bowel syndrome; IBS-D: irritable bowel syndrome with diarrhea; GAD: generalized anxiety disorder

Study	Author name/year	Study design	Sample size	Main points
Study 1	Kaplan et al./2013 [21]	Pilot study	13 patients	This study analyzes the effect of duloxetine in 13 patients with GAD and IBS. It found that duloxetine has a positive impact on IBS and GAD symptoms
Study 2	Sohn et al./2012 [22]	Randomized clinical trial	228 patients	This study compared the effect of tianeptine with amitriptyline on IBS. It used both medications in addition to probiotic. it concluded that both can improve IBS-D, but the side effects of tianeptine limit its use
Study 3	Abdul-Baki et al./2009 [23]	Randomized, double-blind trial	56 patients	Imipramine has a positive impact on IBS symptoms compared to placebo. It assists in improving QoL. Precaution by choosing the right candidate for its use is essential along with starting with low dose
Study 4	Ladabaum et al./2010 [24]	Randomized clinical trial	54 patients	The research concluded that citalopram does not have a positive effect on IBS symptoms in comparison to placebo in non-depressed patients
Study 5	Masand et al./2009 [25]	Double-blind, randomized controlled study	72 patients	Paroxetine has no beneficial effect on pain control in IBS, while it has a positive impact on clinical global impression improvement ratings
Study 6	Talley et al./2008 [26]	Randomized controlled study	51 patients	Neither imipramine nor citalopram has a positive effect on global IBS endpoints
Study 7	Tack et al./2006 [27]	Double-blind, parallel-arm study	23 patients	Citalopram has a positive impact on IBS symptoms. Citalopram’s positive effect is not related to improving depression or anxiety symptoms