If you are in the middle of a flare right now — or just coming out of one, exhausted and raw — this post is for you.
One of the most distressing things about an IBS flare is not knowing when it will end. The uncertainty itself tends to make it worse. And most of the answers available online are frustratingly vague: “it depends,” “anywhere from a few hours to several weeks,” “everyone is different.”
All of that is true. And it is not very helpful when you are in it.
Here is what is actually happening during a flare — and why understanding it changes both how long flares last and how you experience them while they do.
What Is Actually Happening During a Flare
An IBS flare is not a random event. It is a nervous system state — a period in which the gut-brain communication loop has tipped into heightened reactivity and is sustaining itself through a feedback cycle.
Something triggers the gut: a food, a stress, a disrupted night, a difficult conversation, a period of accumulated strain. The gut sends distress signals upward through the vagus nerve to the brain. The brain, already primed toward threat-monitoring if you have IBS, interprets those signals as danger and activates the stress response. Cortisol and stress hormones flood the gut. The gut becomes more sensitive and more reactive. More signals go up. More stress comes down. The loop sustains itself (Konturek et al., 2011).
A flare ends when the nervous system is able to downregulate — when the feedback loop loses enough energy that the gut settles. How quickly that happens depends on several things: the original trigger, the state of your nervous system baseline going into the flare, how much anxiety about the flare is adding fuel to the loop, and whether the circumstances that triggered it have resolved.
Why Some Flares Last Hours and Others Last Weeks
A flare triggered by a single acute stressor — a difficult meal, a one-off anxiety event — often resolves within hours to a day or two once the stressor has passed and the nervous system has had a chance to settle.
A flare that persists for days or weeks is usually being sustained by something ongoing: accumulated life stress, unresolved relational tension, disrupted sleep, a period of significant anxiety, or the anxiety about the flare itself. That last one is particularly important and particularly underrecognized.
The anxiety about the flare — why is this still happening, when will it end, what if it never does — is not a neutral observation. It is an active input into the gut-brain loop. The monitoring, the catastrophizing, the hypervigilance about symptoms — all of this keeps the nervous system in threat mode, which keeps the gut activated, which extends the flare.
Research on gastrointestinal-specific anxiety consistently finds that the degree of symptom-focused attention and worry is one of the strongest predictors of flare severity and duration — independent of the original trigger (Labus et al., 2007). The fear of the flare is part of what sustains it.
What Shortens a Flare
Understanding the mechanism suggests what actually helps.
Reducing the anxiety about the flare — not by suppressing awareness of symptoms, but by changing the relationship with them. Naming what is happening: “This is a nervous system state. It will pass. My job right now is not to fix it but to stop adding fuel.” That cognitive shift — from alarm to accurate observation — is one of the most effective things you can do mid-flare.
Activating the parasympathetic nervous system — the rest-and-digest state your gut needs in order to settle. Slow exhale breathing, warmth on the abdomen, gentle movement, being somewhere safe and calm. You are not trying to end the flare through willpower. You are creating the physiological conditions in which the nervous system can downregulate.
Reducing ongoing stressors where possible — because a flare sustained by unresolved life stress will not fully settle while that stress remains at peak. Sometimes what a prolonged flare most needs is not a gut intervention but an honest look at what the nervous system is responding to.
What to Remember When You Are In It
Flares end. Every single one, eventually, ends. Your nervous system is not designed to stay at peak activation indefinitely — it will downregulate. The question is how quickly, and that question is meaningfully influenced by how you respond to the flare while you are in it.
The response that prolongs flares most reliably is fear — the monitoring, the catastrophizing, the desperate searching for a way to make it stop. The response that shortens them most reliably is the opposite: accurate, compassionate observation, nervous system support, and the steady knowledge that this is a state, not a sentence.
You have gotten through every flare you have ever had. Your track record is one hundred percent.
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
Konturek, P. C., Brzozowski, T., & Konturek, S. J. (2011). Stress and the gut: Pathophysiology, clinical consequences, diagnostic approach and treatment options. Journal of Physiology and Pharmacology, 62(6), 591–599.
Labus, J. S., Mayer, E. A., Chang, L., Bolus, R., & Naliboff, B. D. (2007). The central role of gastrointestinal-specific anxiety in irritable bowel syndrome: Further validation of the visceral sensitivity index. Psychosomatic Medicine, 69(1), 89–98. https://doi.org/10.1097/PSY.0b013e31802e2f24
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
