Up to 15 percent of the general adult population is affected by irritable bowel syndrome (IBS), and most patients struggle to find effective drug therapy. A new guideline1 from the American Gastroenterological Association (AGA) provides these patients and their physician's guidance. The new guideline and accompanying technical review have been published in Gastroenterology, the official journal of the AGA Institute.

"Because no IBS therapy is uniformly effective, many patients describe a history of a variety of treatments alone or in combination. This guideline will help patients and physicians navigate the drug options. It's also important to consider other clinically relevant information, such as a patient's values and preferences, when making treatment decisions," said Shahnaz Sultan, MD, MHSc, an author of the guidelines, from the gastroenterology section, Department of Veteran Affairs Medical Center, North Florida/South Georgia Veterans Health System.

The AGA developed the guideline using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology2 and best practices as outlined by the Institute of Medicine. Despite a large number of published studies on IBS therapies, in most cases, the quality of available data and or the balance of risks and benefits for a particular therapy did not overwhelmingly support the use of particular drugs. Additionally, there are no studies comparing the effectiveness of commonly used drugs to each other nor is there data comparing combinations of therapies to placebo or to each other.

Recognizing these limitations, the AGA Institute guidelines represent a rigorous, evidenced-based summary of extensive literature describing the use of drug treatments for IBS.

Patients with IBS-C (constipation)

  • Recommends using linaclotide (over no drug treatment) in patients with IBS-C. (Strong recommendation; High-quality evidence)
  • Suggests using lubiprostone (over no drug treatment) in patients with IBS-C. (Conditional recommendation; Moderate-quality evidence)
  • Suggests using lubiprostone (over no drug treatment) in patients with IBS-C. (Conditional recommendation; Moderate-quality evidence)

Patients with IBS-D (diarrhea)

  • Suggests using rifaximin (over no drug treatment) in patients with IBS-D. (Conditional recommendation; Moderate-quality evidence)
  • Suggests using alosetron (over no drug treatment) in patients with IBS-D to improve global symptoms. (Conditional recommendation; Moderate evidence)
  • Suggests using loperamide (over no drug treatment) in patients with IBS-D. (Conditional recommendation; Very low-quality evidence)

Patients with IBS

  • Suggests using tricyclic antidepressants (over no drug treatment) in patients with IBS. (Conditional recommendation; Low-quality evidence)
  • Suggests against using selective serotonin reuptake inhibitors for patients with IBS. (Conditional recommendation; Low-quality evidence)
  • Suggests using antispasmodics (over no drug treatment) in patients with IBS. (Conditional recommendation; Low-quality evidence)