CURRENT DIRECTIONS IN RESEARCH ON IRRITABLE BOWEL SYNDROME (IBS): PATHOPHYSIOLOGY, DIAGNOSIS, AND THERAPEUTIC PERSPECTIVES

Abstract

This paper provides a comprehensive review of the current state of knowledge on irritable bowel syndrome (IBS), one of the most common gastrointestinal disorders, currently classified as a disorder of gut–brain interaction (DGBI). The review discusses the epidemiology, pathophysiology, clinical presentation, diagnostic approach, therapeutic management, and emerging research directions in IBS. The prevalence of IBS ranges from 3.8% to as high as 14% of the global population, with significant regional and sex-related differences. IBS is a multifactorial disorder involving disturbances of the gut–brain axis, visceral hypersensitivity, alterations in the gut microbiota (dysbiosis), immune dysfunction, as well as genetic, hormonal, and psychological factors. The clinical manifestations include recurrent abdominal pain, altered bowel habits (constipation-predominant, diarrhea-predominant, and mixed subtypes), abdominal bloating, and extraintestinal symptoms such as fatigue, sleep disturbances, anxiety, and depression. The diagnosis is based on the Rome IV criteria and the exclusion of organic diseases, particularly in the presence of alarm features ("red flags"). A multidisciplinary therapeutic approach includes patient education, dietary interventions (including the low-FODMAP and Mediterranean diets), probiotics, pharmacological treatment tailored to the IBS subtype, and psychological therapies such as cognitive behavioral therapy (CBT) and gut-directed hypnotherapy. Emerging therapeutic strategies include modulation of the gut microbiota through fecal microbiota transplantation (FMT) and next-generation probiotics, as well as mechanism-based pharmacological agents, including elobixibat and olorinab.