Management of irritable bowel syndrome with diarrhea: a review of nonpharmacological and pharmacological interventions

Abstract

Irritable bowel syndrome (IBS) is a common gastrointestinal (GI) condition involving numerous potential causative factors (e.g. alterations in gut microbiota, motility, brain-gut axis). Several interventions are available for the management of patients with IBS, but no universal management algorithm currently exists. The aim of this article is to review interventions that may be considered in the management of patients with IBS with diarrhea (IBS-D). Nonpharmacological interventions include dietary and lifestyle modification, which are generally used as first-line therapy. Probiotics have demonstrated efficacy and safety in patients with IBS, but studies are inconsistent in strains examined, dosing, and treatment duration. Psychological therapies (e.g. cognitive behavioral therapy, hypnotherapy) also may improve IBS symptoms. Pharmacological interventions for the management of IBS-D include the US Food and Drug Administration-approved agents eluxadoline, rifaximin, and alosetron, as well as loperamide, smooth muscle antispasmodics, bile acid sequestrants, and antidepressants (i.e. tricyclic antidepressants, selective serotonin reuptake inhibitors). Eluxadoline and rifaximin have been shown to improve abdominal pain and stool consistency in patients with IBS-D. In addition, data indicate that alosetron improves IBS symptoms; however, it is approved only for women with severe IBS-D. Of the three approved agents, rifaximin has the most favorable safety profile. The risk-benefit ratio is an important consideration with every medication, but is especially important in the treatment of functional GI disorders such as IBS-D. Thus, the most troublesome symptoms, quality of life, symptom intensity, and individual patient preferences should be considered when formulating a management plan for patients with IBS-D.

Keywords: alosetron; diarrhea; efficacy; eluxadoline; irritable bowel syndrome; rifaximin; safety; treatment.

Figure 1.

Percentage of responders to 12 weeks of daily eluxadoline. Responders were defined as patients with a ⩾30% decrease from baseline in worst abdominal pain for ⩾50% of days, and, on the same days, a Bristol Stool Scale score <5. BID, twice daily.

Figure 2.

Percentage of responders to a 2-week course of rifaximin.^, (a) Responders were defined as patients with adequate relief of global IBS symptoms (determined by ‘yes’ or ‘no’ response to the weekly question ‘In regard to all your symptoms of IBS, as compared with the way you felt before you started the study medication, have you, in the past 7 days, had adequate relief of your IBS symptoms?’) for ⩾2 of the first 4 weeks post-treatment. (b) Responders were defined as patients with ⩾30% decrease from baseline in mean weekly pain score and ⩾50% decrease from baseline in the number of days/week with Bristol Stool Scale type 6 or 7 stool for ⩾2 of the first 4 weeks post-treatment. IBS, irritable bowel syndrome; TID, three times daily.

Figure 3.

Percentage of women with severe IBS-D with response to 12 weeks of daily alosetron. Responders were defined as patients with either moderate or substantial improvement in global IBS symptoms, as determined by response to the question ‘Compared to the way you usually felt during the 3 months before you entered the study, are your IBS symptoms over the past 4 weeks substantially worse, moderately worse, slightly worse, no change, slightly improved, moderately improved, or substantially improved?’ BID, twice daily; IBS, irritable bowel syndrome; QD, once daily.

Figure 4.

Proposed treatment algorithm for management of patients with irritable bowel syndrome with diarrhea. FODMAP, fermentable oligosaccharides, disaccharides, monosaccharides, and polyols; TCA, tricyclic antidepressant.