Does IBS Cause Anxiety, Or Does Anxiety Cause IBS?
It’s half past one in the morning and your stomach’s doing that thing again. Not pain exactly, more a low, gripping unease that won’t settle whichever way you lie. There’s a meeting tomorrow you can’t move, and somewhere underneath the discomfort a second, smaller worry starts up: what if tomorrow’s a bad one. By the time the alarm goes you’re already tired, and being tired makes everything feel that bit closer to the edge.
Somewhere along the way, somebody’s probably suggested to you that the worry is the real problem. That if you were less anxious, your gut would behave itself. That’s a hard thing to hear when the symptoms are the loudest, most physical thing in your day. A large study published earlier this year looked at that question properly, in both directions at once, and the answer’s more interesting, and a good deal kinder, than the version you’ve been handed.
This week’s research: the risk runs both ways, not one
A team led by Ya-Ju Yu at the National Defence Medical University in Taiwan used their country’s national health insurance records, which cover almost everybody in the country, and drew a random sample of one million adults followed from 2000 to 2015. Then they asked the same question twice, once in each direction.
First they took 18,402 adults who’d just been diagnosed with depression or an anxiety disorder, and matched each one to somebody of the same age and sex who had neither. That gave them 36,804 people to follow for an average of about seven years. More of the distress group went on to be diagnosed with irritable bowel syndrome (IBS) than the matched group did, and that still held once they’d accounted for income, where people lived, how often they used healthcare, and a list of physical conditions.
Then they turned it round. They took 16,110 adults newly diagnosed with IBS, none of them carrying any earlier record of depression or anxiety, and matched them the same way. Over just under seven years, more of the IBS group went on to be diagnosed with depression or anxiety than the matched group did. The pattern was stronger in women, and stronger in adults under forty.
Here’s the part that matters most, and it’s easy to skim past. The two directions came out at a similar size. Neither one dwarfed the other.
One other thing stood out from everything else they measured. Of all the conditions people were carrying alongside IBS, sleep disorders had the strongest link in both directions, ahead of every other physical condition on their list.
Why this matters for you. This isn’t a study showing that anxious people give themselves IBS. It’s a study showing that gut and mood pull on each other, fairly evenly, over years. If your symptoms arrived first and low mood or worry followed, that’s a documented pattern in tens of thousands of people, not a personal failing. And if the distress came first, that doesn’t make your symptoms any less physically real.
Where it’s weak, and it’s worth knowing: it’s observational, so it watches what happens rather than testing anything. It’s built from diagnostic codes in an insurance database rather than from symptom questionnaires, so it only sees the people who went to a doctor and got a label. And it’s from Taiwan, not the UK, so the healthcare people met along the way wasn’t the NHS. It shows these things travel together over time. It can’t prove one causes the other, and it didn’t test any treatment on anybody.
Why a two-way street is exactly what you’d expect
IBS is classified as a disorder of gut-brain interaction, and that phrase is doing real work. Your gut and your brain are wired together and they talk constantly, through the nervous system, through hormones, through the immune system. Signals travel up and signals travel down. When that conversation becomes oversensitive, ordinary gut activity, the sort that wouldn’t register for anybody else, gets read as pain or urgency. That’s visceral hypersensitivity, which is a change in signalling rather than imagination, and we went into it properly in Your Head Can Calm Your Gut.
Once you see the wiring as two-directional, a finding like this stops being surprising. Symptoms raise vigilance. Vigilance raises arousal. Arousal changes how the gut moves, and it lowers the point at which ordinary sensation gets read as pain. Poor sleep sits inside that loop and makes every part of it worse, which is very likely why sleep came out as the strongest signal here rather than one of the other conditions. Nobody in that loop is to blame for it. The loop just keeps itself going. If you’d like the fuller picture of how the worry layer behaves over a year, and how much of it can ease, that was an earlier edition here.
It’s also why my own work is cognitive behavioural hypnotherapy rather than hypnosis on its own. It brings together three things aimed at that same maintaining loop from different angles: cognitive behavioural therapy, which is working with what you do with the thoughts; mindfulness, which is changing how you relate to the sensations while they’re there; and gut-directed hypnotherapy, which works directly on gut sensitivity itself. Gut-directed hypnotherapy carries a strong recommendation in the 2021 British Society of Gastroenterology guideline for IBS, and NICE lists it as an option where IBS hasn’t responded to first-line treatment after twelve months. That’s what the guidelines say. It isn’t a promise about what will happen for you, and no approach helps everybody.
Your top tip this week
Give the last hour before bed back to your body. Sleep was the strongest link this study found in either direction, and unlike your genes or your diagnosis, the hour before you sleep is something you can get hold of this week without waiting for an appointment. Pick a finishing time for work, screens and admin, and hold it. Then, before you get into bed, write tomorrow’s three real jobs on a piece of paper, because a brain that’s put the list down somewhere solid rehearses it less at one in the morning. Finish with ten minutes lying down doing something slow and undemanding, a relaxation recording or simply longer out-breaths than in-breaths. You’re not trying to fix your gut in that hour. You’re lowering the overall level of alert your system goes to bed carrying, and this study suggests that level isn’t a side issue.
The takeaway
The question was never really whether your gut caused your head or your head caused your gut. It’s a loop, it runs in both directions at roughly equal strength, and it’s been running quietly for years in tens of thousands of people who were told it only went one way. That reframe matters, because a loop can be interrupted at more than one point. You don’t have to find the original cause to change what’s happening now.
Wherever you are right now
If you haven’t had a firm diagnosis yet, start with your GP. Gut symptoms have several possible causes and some of them need ruling out, so get that done first. It also gives everything else you try a clear starting point.
If you were diagnosed a while ago and you’re still struggling, you’re exactly who the guidelines had in mind for psychological approaches. Try the hour before bed this week, and keep in mind that you’re working on the loop rather than hunting for the one thing that started it.
If you’re a GP or a gastroenterologist reading this, the referrer brief for gut-directed hypnotherapy, with the guideline positions set out and their limits stated, is available on request.
If you’d like the science in plain English once a week, plus one thing to try, join Gut Feelings at mindyourguts.co.uk/free-relaxation-page. The free relaxation recording comes with it.
About Mind Your Guts
Mind Your Guts is the Irritable Bowel Syndrome (IBS) blog written by Kathryn Dunn, a cognitive behavioural hypnotherapist based in York, Yorkshire and working online. One piece of gut-brain research each week, in plain language, and one thing worth trying. More at mindyourguts.co.uk/gut-feelings.
Twelve Minutes of Calm. A free relaxation recording, about twelve minutes, for the times you want to feel calmer. It’s a general relaxation recording rather than a treatment for anything. Download it at mindyourguts.co.uk/free-relaxation-page and you’ll also join Gut Feelings, my weekly email, which carries each new post to your inbox along with a bit extra.
Hypnotherapy works alongside conventional medical care, never in place of it. This blog shares research for general information and is not a substitute for medical advice. Only a doctor can diagnose IBS. Always consult your GP or another relevant health professional. If your symptoms are new, changing, or accompanied by warning signs such as bleeding, unexplained weight loss, or persistent pain, please see your GP.
Sources
•Bidirectional associations between irritable bowel syndrome and psychological distress: a longitudinal population-based study, Yu YJ, Huang YC, Weng TH, Huang HY, Lai FC, Lin TC, Yu PC, Chien WC, Psychological Medicine, 2026;56:e45 (doi:10.1017/S0033291726103328, PMID 41667938)
Irritable bowel syndrome in adults: diagnosis and management, NICE clinical guideline CG61
