CURRENT DIRECTIONS IN RESEARCH ON IRRITABLE BOWEL SYNDROME (IBS): PATHOPHYSIOLOGY, DIAGNOSIS, AND THERAPEUTIC PERSPECTIVES
DOI:
https://doi.org/10.31435/ijitss.4(52).2026.6255Keywords:
Irritable Bowel Syndrome, Epidemiology, Pathophysiology, Clinical Presentation, Diagnosis, TreatmentAbstract
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.
References
Accarie, A., Toth, J., Wauters, L., Farré, R., Tack, J., & Vanuytsel, T. (2022). Estrogens play a critical role in stress-related gastrointestinal dysfunction in a spontaneous model of disorders of gut–Brain interaction. Cells, 11(7), 1214.
Adeyemo MA, Spiegel BM, Chang L. Association among somatization, psychological distress, and IBS. Am J Gastroenterol. 2010;105(4):904-912. https://doi.org/10.1038/ajg.2010.73
Aliyu, A. I., Katsumata, R., Törnblom, H., & Simrén, M. (2025). Gastrointestinal transit abnormalities in irritable bowel syndrome and their relation to symptoms. Expert Review of Gastroenterology & Hepatology, 19(5), 447-454. https://doi.org/10.1080/17474124.2025.2493867
Almario, C. V., Sharabi, E., Chey, W. D., Lauzon, M., Higgins, C. S., & Spiegel, B. M. (2023). Prevalence and burden of illness of Rome IV irritable bowel syndrome in the united states: Results from a nationwide cross-sectional study. Gastroenterology, 165(6), 1475-1487. https://doi.org/10.1053/j.gastro.2023.08.010
Almario, C. V., Sharabi, E., Chey, W. D., Lauzon, M., Higgins, C. S., & Spiegel, B. M. (2023). Prevalence and burden of illness of Rome IV irritable bowel syndrome in the united states: Results from a nationwide cross-sectional study. Gastroenterology, 165(6), 1475-1487. https://doi.org/10.1053/j.gastro.2023.08.010
Arif TB, Ali SH, Bhojwani KD, Sadiq M, Siddiqui AA, Ur-Rahman A, Khan MZ, Hasan F, Shahzil M. Global prevalence and risk factors of irritable bowel syndrome from 2006 to 2024 using the Rome III and IV criteria: a meta-analysis. Eur J Gastroenterol Hepatol. 2025 Dec 1;37(12):1314-1325. https://doi.org/10.1097/MEG.0000000000002994. Epub 2025 Apr 30. PMID: 40359286
Barbara, G., Grover, M., Bercik, P., Corsetti, M., Ghoshal, U. C., Ohman, L., & Rajilić-Stojanović, M. (2019). Rome foundation working team report on post-infection irritable bowel syndrome. Gastroenterology, 156(1), 46-58.
Beatty, J. K., Akierman, S. V., Motta, J. P., Muise, S., Workentine, M. L., Harrison, J. J., ... & Buret, A. G. (2017). Giardia duodenalis induces dysbiosis of human intestinal microbiota.; hasler, w. L., Grabauskas, G., Singh, P., & Owyang, C. (2022). Mast cell mediation of visceral sensation and permeability in irritable bowel syndrome. Neurogastroenterology & Motility, 34(7), e14339.;
Beatty, J. K., Bhargava, A., & Buret, A. G. (2014). Post-infectious irritable bowel syndrome: Mechanistic insights into chronic disturbances following enteric infection. World journal of gastroenterology: WJG, 20(14), 3976966
Black CJ, Drossman DA, Talley NJ, Ruddy J, Ford AC. Functional gastrointestinal disorders: advances in understanding and management. Lancet. 2020;396(10263):1664-1674. https://doi.org/10.1016/S0140-6736(20)32115-2
Chang, L., Cash, B. D., Lembo, A., Kunkel, D. C., English, B. A., Lindstrom, B., ... & Tack, J. (2023). Efficacy and safety of olorinab, a full agonist of the cannabinoid receptor 2, for the treatment of abdominal pain in patients with irritable bowel syndrome: Results from a phase 2b randomized placebo‐controlled trial (captivate). Neurogastroenterology & Motility, 35(5), e14539.
Cheng, K., Lee, C., Garniene, R., Cabral, H., & Weber, H. C. (2024). Epidemiology of irritable bowel syndrome in a large academic safety-net hospital. Journal of Clinical Medicine, 13(5), 1314. https://doi.org/10.1053/j.gastro.2023.08.010
Cheng, K., Lee, C., Garniene, R., Cabral, H., & Weber, H. C. (2024). Epidemiology of irritable bowel syndrome in a large academic safety-net hospital. Journal of Clinical Medicine, 13(5), 1314. https://doi.org/10.1053/j.gastro.2023.08.010
Cheng, K., Lee, C., Garniene, R., Cabral, H., & Weber, H. C. (2024). Epidemiology of irritable bowel syndrome in a large academic safety-net hospital. Journal of Clinical Medicine, 13(5), 1314. https://doi.org/10.1053/j.gastro.2023.08.010)
Cheng, K., Lee, C., Garniene, R., Cabral, H., & Weber, H. C. (2024). Epidemiology of irritable bowel syndrome in a large academic safety-net hospital. Journal of Clinical Medicine, 13(5), 1314. https://doi.org/10.1053/j.gastro.2023.08.010
Cheng, K., Lee, C., Garniene, R., Cabral, H., & Weber, H. C. (2024). Epidemiology of irritable bowel syndrome in a large academic safety-net hospital. Journal of Clinical Medicine, 13(5), 1314. https://doi.org/10.1053/j.gastro.2023.08.010
Cheng, K., Lee, C., Garniene, R., Cabral, H., & Weber, H. C. (2024). Epidemiology of irritable bowel syndrome in a large academic safety-net hospital. Journal of Clinical Medicine, 13(5), 1314. https://doi.org/10.1053/j.gastro.2023.08.010
Chey WD, Kurlander J, Eswaran S. Irritable bowel syndrome: a clinical review. JAMA. 2015;313(9):949-958. https://doi.org/10.1001/jama.2015.0954
Chey WD, Lembo AJ, Lavins BJ, et al. Linaclotide for IBS with constipation. N Engl J Med. 2012;367:542-552. https://doi.org/10.1056/NEJMoa1205055
Didari T, Mozaffari S, Nikfar S, Abdollahi M. Effectiveness of probiotics in IBS: meta-analysis. World J Gastroenterol. 2015;21(10):3072-3084. https://doi.org/10.3748/wjg.v21.i10.3072
Ding, L., Duan, J., Yang, T., Yuan, M., Ma, A. H., & Qin, Y. (2025). Efficacy of fermented foods in irritable bowel syndrome: A systematic review and meta-analysis of randomized controlled trials. Frontiers in Nutrition, 11, 1494118.
Drossman, D. A., & Hasler, W. L. (2016). Rome IV—functional gi disorders: Disorders of gut-brain interaction. Gastroenterology, 150(6), 1257-1261.. https://doi.org/10.1053/j.gastro.2016.02.032
Dudzińska, E. (2016). Wpływ mikroflory jelitowej na rozwój zespołu jelita drażliwego. Medycyna Środowiskowa-Environmental Medicine, 19(3), 70-76.
Fond G, Loundou A, Hamdani N, Boukouaci W, et al. Anxiety and depression comorbidities in irritable bowel syndrome (IBS): a systematic review and meta-analysis. Eur Arch Psychiatry Clin Neurosci. 2014;264(8):651-660. https://doi.org/10.1007/s00406-014-0502-z
Ford AC, Lacy BE, Harris LA, Quigley EMM, Moayyedi P. Effect of antidepressants and psychological therapies in IBS: an updated systematic review and meta-analysis. Am J Gastroenterol. 2019;114(1):21-39. https://doi.org/10.1038/s41395-018-0222-5
Ford AC, Lacy BE, Talley NJ. Irritable bowel syndrome. N Engl J Med. 2020;382:1240-1250. https://doi.org/10.1056/NEJMra1907796
Ford AC, Moayyedi P, Lacy BE, et al. American College of Gastroenterology monograph on the management of irritable bowel syndrome. Am J Gastroenterol. 2014;109(S1):S2-S26. https://doi.org/10.1038/ajg.2014.187
Gomersall, B. (2025). Digestive disease week 2025. The Lancet Gastroenterology & Hepatology, 10(7), 618.
Gotsis, E., Anagnostis, P., Mariolis, A., Vlachou, A., Katsiki, N., & Karagiannis, A. (2015). Health benefits of the mediterranean diet: An update of research over the last 5 years. Angiology, 66(4), 304-318.
Guasch‐Ferré, M., & Willett, W. C. (2021). The mediterranean diet and health: A comprehensive overview. Journal of internal medicine, 290(3), 549-566.
Halmos EP, Power VA, Shepherd SJ, Gibson PR, Muir JG. A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology. 2014;146(1):67-75. https://doi.org/10.1053/j.gastro.2013.09.046
Huang, K. Y., Wang, F. Y., Lv, M., Ma, X. X., Tang, X. D., & Lv, L. (2023). Irritable bowel syndrome: Epidemiology, overlap disorders, pathophysiology and treatment. World Journal of Gastroenterology, 29(26), 4120. https://doi.org/10.3748/wjg.v29.i26.4120
Ianiro G, Eusebi LH, Black CJ, Gasbarrini A, Cammarota G, Ford AC. Fecal microbiota transplantation for IBS: systematic review and meta-analysis. Am J Gastroenterol. 2019;114(7):1043-1050. https://doi.org/10.14309/ajg.0000000000000198
Johannesson E, Simrén M, Strid H, Bajor A, Sadik R. Physical activity improves symptoms in irritable bowel syndrome: a randomized controlled trial. Am J Gastroenterol. 2011;106(5):915-922. https://doi.org/10.1038/ajg.2010.480
Khan, M. T., Dwibedi, C., Sundh, D., Pradhan, M., Kraft, J. D., Caesar, R., ... & Bäckhed, F. (2023). Synergy and oxygen adaptation for development of next-generation probiotics. Nature, 620(7973), 381-385.
Lacy BE, Mearin F, Chang L, et al. Bowel Disorders. Gastroenterology. 2016;150(6):1393-1407. https://doi.org/10.1053/j.gastro.2016.02.031
Lacy BE, Mearin F, Chang L, et al. Bowel Disorders. Gastroenterology. 2016;150(6):1393-1407. https://doi.org/10.1053/j.gastro.2016.02.031
Laird KT, Tanner-Smith EE, Russell AC, Hollon SD, Walker LS. Short-term and long-term efficacy of psychological therapies for IBS. Clin Gastroenterol Hepatol. 2016;14(7):937-947. https://doi.org/10.1016/j.cgh.2015.11.020
Lei, Y., Sun, X., Ruan, T., Lu, W., Deng, B., Zhou, R., & Mu, D. (2025). Effects of probiotics and diet management in patients with irritable bowel syndrome: A systematic review and network meta-analysis. Nutrition Reviews, nuae217.
Lembo AJ, Lacy BE, Zuckerman MJ, et al. Eluxadoline for IBS with diarrhea. N Engl J Med. 2016;374:242-253. https://doi.org/10.1056/NEJMoa1505180
Lo, S. W., Hung, T. H., Lin, Y. T., Lee, C. S., Chen, C. Y., Fang, C. J., & Lai, P. C. (2024). Clinical efficacy and safety of faecal microbiota transplantation in the treatment of irritable bowel syndrome: A systematic review, meta-analysis and trial sequential analysis. European Journal of Medical Research, 29(1), 464.
Lovell, R. M., & Ford, A. C. (2012). Global prevalence of and risk factors for irritable bowel syndrome: A meta-analysis. Clinical gastroenterology and hepatology, 10(7), 712-721. https://doi.org/10.1016/j.cgh.2012.02.029
Lupu, V. V., Ghiciuc, C. M., Stefanescu, G., Mihai, C. M., Popp, A., Sasaran, M. O., ... & Lupu, A. (2023). Emerging role of the gut microbiome in post-infectious irritable bowel syndrome: A literature review. World Journal of Gastroenterology, 29(21), 3241.
Mauney, E. E. (2025). Erin mauney: Psychedelics as modulators of the gut-brain interaction. Psychedelics, 1(aop), 1-3.
Mayer EA. Gut feelings: the emerging biology of gut–brain communication. Nat Rev Neurosci. 2011;12(8):453-466. https://doi.org/10.1038/nrn3071
Meyers, N. L., & Hickling, R. I. (2008). Pharmacology and metabolism of renzapride: A novel therapeutic agent for the potential treatment of irritable bowel syndrome. Drugs in R&D, 9(1), 37-63.
Miller V, Carruthers HR, Morris J, Hasan SS, Archbold S, Whorwell PJ. Hypnotherapy for IBS: long-term follow-up. Aliment Pharmacol Ther. 2015;41(3):301-312. https://doi.org/10.1111/apt.13030
Mudyanadzo, T. A., Hauzaree, C., Yerokhina, O., Architha, N. N., & Ashqar, H. M. (2018). Irritable bowel syndrome and depression: A shared pathogenesis. Cureus, 10(8)
Nakajima, A., Taniguchi, S., Kurosu, S., Gillberg, P. G., Mattsson, J. P., & Camilleri, M. (2019). Efficacy, long‐term safety, and impact on quality of life of elobixibat in more severe constipation: Post hoc analyses of two phase 3 trials in japan. Neurogastroenterology & Motility, 31(5), e13571.
Oka, P., Parr, H., Barberio, B., Black, C. J., Savarino, E. V., & Ford, A. C. (2020). Global prevalence of irritable bowel syndrome according to Rome III or IV criteria: A systematic review and meta-analysis. The lancet Gastroenterology & hepatology, 5(10), 908-917.
Peters, S. L., Muir, J. G., & Gibson, P. R. (2015). Gut‐directed hypnotherapy in the management of irritable bowel syndrome and inflammatory bowel disease. Alimentary pharmacology & therapeutics, 41(11), 1104-1115.
Peters, S. L., Yao, C. K., Philpott, H., Yelland, G. W., Muir, J. G., & Gibson, P. R. (2016). Randomised clinical trial: The efficacy of gut‐directed hypnotherapy is similar to that of the low FODMAP diet for the treatment of irritable bowel syndrome. Alimentary pharmacology & therapeutics, 44(5), 447-459.
Pimentel M, Lembo A, Chey WD, et al. Rifaximin therapy for patients with IBS without constipation. N Engl J Med. 2011;364:22-32. https://doi.org/10.1056/NEJMoa1004409
Ritchie, J. (1973). Pain from distension of the pelvic colon by inflating a balloon in the irritable colon syndrome. Gut, 14(2), 125-132.
Schmulson i inni, 2017 Schmulson, M. J., & Drossman, D. A. (2017). What is new in Rome IV. Journal of neurogastroenterology and motility, 23(2), 151. https://doi.org/10.5056/jnm16214
Spiller, R., & Lam, C. (2012). An update on post-infectious irritable bowel syndrome: Role of genetics, immune activation, serotonin and altered microbiome. Journal of neurogastroenterology and motility, 18(3), 258.
Takeoka, A., Kimura, T., Hara, S., Hamaguchi, T., Fukudo, S., & Tayama, J. (2023). Prevalence of irritable bowel syndrome in japan, china, and south korea: An international cross-sectional study. Journal of neurogastroenterology and motility, 29(2), 229. https://doi.org/10.5056/jnm22037
Takeoka, A., Kimura, T., Hara, S., Hamaguchi, T., Fukudo, S., & Tayama, J. (2023). Prevalence of irritable bowel syndrome in japan, china, and south korea: An international cross-sectional study. Journal of neurogastroenterology and motility, 29(2), 229. https://doi.org/10.5056/jnm22037
Takeoka, A., Kimura, T., Hara, S., Hamaguchi, T., Fukudo, S., & Tayama, J. (2023). Prevalence of irritable bowel syndrome in japan, china, and south korea: An international cross-sectional study. Journal of neurogastroenterology and motility, 29(2), 229. https://doi.org/10.5056/jnm22037
Van der Lelie, D., Oka, A., Taghavi, S., Umeno, J., Fan, T. J., Merrell, K. E., ... & Sartor, R. B. (2021). Rationally designed bacterial consortia to treat chronic immune-mediated colitis and restore intestinal homeostasis. Nature communications, 12(1), 3105.
Wang, G., Fan, Y., Zhang, G., Cai, S., Ma, Y., Yang, L., ... & Zeng, X. (2024). Microbiota-derived indoles alleviate intestinal inflammation and modulate microbiome by microbial cross-feeding. Microbiome, 12(1), 59.
Xie, C. R., Tang, B., Shi, Y. Z., Peng, W. Y., Ye, K., Tao, Q. F., ... & Chen, M. (2022). Low FODMAP diet and probiotics in irritable bowel syndrome: A systematic review with network meta-analysis. Frontiers in pharmacology, 13, 853011
You, X. Y., Zhang, H. Y., Han, X., Wang, F., Zhuang, P. W., & Zhang, Y. J. (2021). Intestinal mucosal barrier is regulated by intestinal tract neuro-immune interplay. Frontiers in pharmacology, 12, 659716
Zhao, H. J., Zhang, X. J., Zhang, N. N., Yan, B., Xu, K. K., Peng, L. H., & Pan, F. (2022). Fecal microbiota transplantation for patients with irritable bowel syndrome: A meta-analysis of randomized controlled trials. Frontiers in Nutrition, 9, 890357.
Zhou C, Zhao E, Li Y, Jia Y. Mindfulness interventions for IBS: a systematic review and meta-analysis. J Psychosom Res. 2019;120:29-38. https://doi.org/10.1016/j.jpsychores.2019.03.013
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Marlena Radzka, Izabela Radzka, Paweł Budzik, Szymon Marciszuk, Jonatan Rataj, Michalina Bawor-Mostowa, Amelia Kosowska
This work is licensed under a Creative Commons Attribution 4.0 International License.
All articles are published in open-access and licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0). Hence, authors retain copyright to the content of the articles.
CC BY 4.0 License allows content to be copied, adapted, displayed, distributed, re-published or otherwise re-used for any purpose including for adaptation and commercial use provided the content is attributed.
