Irritable Bowel Syndrome: Current Landscape of Diagnostic Guidelines and Therapeutic Strategies

Irritable bowel syndrome (IBS) is a disorder of the gut–brain axis with pronounced adverse effects on physical health, psychological health, and overall quality of life. Diagnostic strategies can vary, highlighting a need to synthesize best-practice guidelines. Particularly, the American College of Gastroenterology and the British Society of Gastroenterology both support a positive diagnostic strategy; evaluation with C-reactive protein, fecal calprotectin, and fecal lactoferrin; and evaluation with celiac disease serology. Both guidelines do not support routine colonoscopy, and both differ in recommendations for anorectal physiology testing. Given there is currently no curative treatment available, IBS management focuses on symptomatic relief, and challenges exist in achieving and maintaining this relief. Many treatments, both pharmacologic and nonpharmacologic, exist to alleviate the uncomfortable, painful symptoms of the disorder; however, stratifying the quality of evidence behind each option is critical for application to clinical management and for tailoring this management to each patient. Lifestyle adjustments, especially in relation to diet, can be effective first-line therapies and supplements to pharmacologic therapy. Pharmacologic treatment is broadly categorized in accordance with the subtypes of IBS, with indications for different populations and mechanisms that work to target components of IBS pathophysiology. The aim of this article is to comprehensively compare updated diagnostic guidelines, review standard treatments, and outline recent pharmacologic advancements.