If you have recently been diagnosed with irritable bowel syndrome — or if you have been living with gut symptoms for years and are only now starting to understand what they are — this post is for you.
IBS is one of the most common digestive conditions in the world, affecting an estimated 10 to 15 percent of the global population (Mearin et al., 2016). And yet most people who have it feel profoundly alone in it, largely because it is invisible, frequently misunderstood, and dismissed far too often with a “just” in front of it.
“It’s just IBS.”
This post is my attempt to give you a better explanation than that.
What IBS Actually Is
IBS stands for irritable bowel syndrome. It is classified by researchers as a disorder of gut-brain interaction — meaning the problem is not in the structure or tissue of your digestive system, but in the communication between your gut and your brain (Mearin et al., 2016).
A colonoscopy will not show damage. Blood tests will not reveal inflammation. Your gut, examined structurally, looks normal. And that is genuinely good news — it means something serious has been ruled out. But it is also the source of one of the most painful experiences of living with IBS: being told everything looks fine when your daily reality is anything but.
What is not fine is the communication pathway. The gut and brain are in constant two-way conversation through the gut-brain axis — a network of nerve pathways, hormones, and immune signals. In IBS, that conversation has become dysregulated. The gut sends signals the brain interprets as threat. The brain sends stress signals the gut responds to with pain, urgency, and unpredictability. The two amplify each other in a loop that can feel impossible to escape (Rao & Gershon, 2016).
What IBS Feels Like
IBS symptoms vary considerably from person to person, but the most common include abdominal pain or cramping, bloating and distension, diarrhea, constipation, or an unpredictable alternation between the two, urgency, and the sense that bowel movements are incomplete.
Many people also experience symptoms beyond the gut — fatigue, sleep disturbance, anxiety, low mood, and what is increasingly recognized as brain fog. These are not separate problems happening alongside IBS. They are part of the same dysregulated gut-brain system.
IBS is typically categorized into subtypes: IBS-D (diarrhea-predominant), IBS-C (constipation-predominant), IBS-M (mixed), and IBS-U (unsubtyped). Most people find their subtype shifts over time, which is one of the reasons IBS can feel so unpredictable.
What Causes IBS
IBS does not have a single cause. It is what researchers call a multifactorial condition — meaning multiple things contribute, and the balance differs from person to person.
What the research consistently identifies as significant contributors includes: a sensitized gut-brain axis, altered gut motility, visceral hypersensitivity (a lowered pain threshold in the gut), changes in gut microbiome composition, and — critically — psychological and psychosocial factors including stress, anxiety, trauma history, and early adverse experiences (Mayer et al., 2023).
IBS heritability is only about 5.8 percent — remarkably low, meaning genetics accounts for very little of IBS risk (Mayer et al., 2023). What accounts for most of it is environmental: what happened to you, what your nervous system learned, how your stress response developed. This is not a reason for shame. It is a reason for hope — because what was learned can be unlearned, with the right support.
What IBS Is Not
IBS is not inflammatory bowel disease (IBD) — conditions like Crohn’s disease or ulcerative colitis, which involve structural inflammation and damage to the digestive tract. IBS is not colon cancer. It is not a progressive disease that will damage your gut over time.
It is also not imaginary. Not “just anxiety.” Not something you would resolve if you simply relaxed or changed your diet. It is a real, diagnosable, well-researched condition with biological mechanisms that are increasingly well understood — and increasingly well treated.
What Helps
The treatments with the strongest evidence for IBS are the ones that address the gut-brain communication directly. Gut-directed CBT has shown significant lasting improvement in over 60 percent of people who complete it (Lackner et al., 2018). Gut-directed hypnotherapy has decades of research behind it and produces durable results for the majority of people who respond (Adler et al., 2025). Mindfulness-Based Stress Reduction has consistent evidence for pain reduction and quality of life improvement (Altobelli et al., 2022).
Dietary approaches and medication play a role for many people. But for the majority of people with IBS, the nervous system layer — the gut-brain communication that drives symptoms — is where the most significant and lasting change happens.
You are not stuck with this. And you do not have to figure it out alone.
About the author
Susan Liddy, MAMFT is a GI Psychotherapist and doctoral candidate in Integrative Health, specializing in nervous system-informed care for IBS and disorders of gut-brain interaction. Georgia residents are welcome to schedule a free consultation at www.susanliddy.com.
For educational purposes only. Not medical or psychological advice. Susan Liddy, MAMFT
References
Adler, E. C., Levine, E. H., Ibarra, A. N., Boparai, E. S., Hung, Y.-Y., McCrary, Q. D., & Lee, J. K. (2025). Gut-directed hypnotherapy for irritable bowel syndrome: A systematic review and meta-analysis. Neurogastroenterology & Motility, 37(4), e70037. https://doi.org/10.1111/nmo.70037
Altobelli, E., Angeletti, P. M., Profeta, V. F., & Petrocelli, R. (2022). Meditation and irritable bowel syndrome: A systematic review and meta-analysis. Journal of Clinical Medicine, 11(21), 6516. https://doi.org/10.3390/jcm11216516
Lackner, J. M., Jaccard, J., Keefer, L., Brenner, D. M., Firth, R. S., Gudleski, G. D., Hamilton, F. A., Katz, L. A., Krasner, S. S., Ma, C.-X., Radziwon, C. D., & Sitrin, M. D. (2018). Improvement in gastrointestinal symptoms after cognitive behavior therapy for refractory irritable bowel syndrome. Gastroenterology, 155(1), 47–57. https://doi.org/10.1053/j.gastro.2018.03.063
Mayer, E. A., Ryu, H. J., & Bhatt, R. R. (2023). The neurobiology of irritable bowel syndrome. Molecular Psychiatry, 28(4), 1451–1465. https://doi.org/10.1038/s41380-023-01972-w
Mearin, F., Lacy, B. E., Chang, L., Chey, W. D., Lembo, A. J., Simren, M., & Spiller, R. (2016). Bowel disorders. Gastroenterology, 150(6), 1393–1407. https://doi.org/10.1053/j.gastro.2016.02.031
Rao, M., & Gershon, M. D. (2016). The bowel and beyond: The enteric nervous system in neurological disorders. Nature Reviews Gastroenterology & Hepatology, 13(9), 517–528. https://doi.org/10.1038/nrgastro.2016.107
