Irritable bowel syndrome (IBS) is a highly prevalent, chronic disorder that significantly reduces patients' quality of life.¹ The management of IBS has been previously examined in several recent monographs, reviews and position statements that provide management recommendations based on the meta-analysis and/or expert opinions.^2-4 However, essential diagnostic and treatment recommendations have not been formally evaluated by the American College of Gastroenterology (ACG) using rigorous Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology.¹ In a recent paper published in the American Journal of Gastroenterology, the ACG has developed their first-ever clinical guideline for the management of IBS.¹

IBS is a common condition encountered by primary care physicians with an estimated local prevalence of 6.6%.⁵ It is believed to be a multifactorial disease involving motility dysfunction, visceral hypersensitivity, psychiatric co-morbidity, neuroendocrine dysfunction, genetics and epigenetics, dysbiosis, diet and immune activation.⁶ Advances in diagnostic testing and therapeutic options for patients with IBS have led to the development of the ACG clinical guideline in order to identify and answer key diagnostic and clinical questions relevant to the field of IBS.¹

Clinically relevant questions were developed by a panel of experts who focus their clinical and research efforts on disorders of gutbrain interaction.¹ The group formulated 25 key clinically important questions; 9 questions focusing on diagnostic testing and 16 questions focusing on therapeutic options.¹ These questions were answered by a comprehensive international literature search.¹ Trained GRADE methodologists analyzed the data to assess the quality of evidence and the given strength of the recommendation.¹ Consensus was then obtained using a modified Delphi approach.¹

Highlights of the recommendations are summarized as follows:¹

• Check fecal calprotectin or fecal lactoferrin and C-reactive protein in patients without alarm features and with suspected IBS and diarrhea symptoms to rule out inflammatory bowel disease
• Use a positive diagnostic strategy as compared to a diagnostic strategy of exclusion for patients with symptoms of IBS to improve time to initiate appropriate therapy and improve cost-effectiveness
• Do not do routine stool testing for enteric pathogens in all patients with IBS
• Do not do routine colonoscopy in patients with IBS symptoms younger than 45 years without warning signs
• Categorize patients based on an accurate IBS subtype to improve patient therapy
• Do not test for food allergies and food sensitivities in all patients with IBS unless there are reproducible symptoms concerning for a food allergy
• Do anorectal physiology testing in patients with IBS and symptoms suggestive of a pelvic floor disorder and/or refractory constipation not responsive to standard medical therapy
• Consider a limited trial of a low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet in patients with IBS to improve global symptoms
• Consider soluble but not insoluble fiber to be used to treat global IBS symptoms
• Do not use antispasmodics which are currently available in the United States to treat global IBS symptoms
• Use peppermint to provide relief of global IBS symptoms
• Do not use probiotics for the treatment of global IBS symptoms
• Use tricyclic antidepressants (TCAS) to treat global symptoms of IBS • Use gut-directed psychotherapies to treat global IBS symptoms
• Use fecal transplant for the treatment of global IBS symptoms

Overall, the panel published the new guideline to help guide both practitioners and researchers in managing IBS, but also noted that there are still significant gaps in our knowledge regarding the disease.¹ Further research is needed to better understand the role of the gut microbiome in patients with IBS and the genesis of visceral pain.¹ Identification of biomarkers to predict treatment response is also essential, and large head-to-head trials comparing different therapeutic modalities are needed to better provide individualized care.¹ The panel thus concluded that, “Undoubtedly, information obtained from these studies will influence new guidelines, assist in pharmaceutical and diet development, direct changes in study design and inform regulatory agencies.”