IBS has no single cause that a doctor can find and remove. It is a disorder of gut–brain interaction, in which several things combine: changes in how the gut moves, an oversensitive gut, altered immune activity and gut bacteria, and differences in how the brain processes gut signals.[2] That is why no one treatment switches it off for good. UK guidelines describe IBS as chronic, with fluctuating symptoms, in most people who see a doctor for it, while noting that few studies have followed patients for longer than a year.[1] The studies that have done so show that IBS is far from fixed.
Does IBS get better over time?
Often, yes. Symptoms shift a lot from year to year, and they improve or disappear in a large share of people:
| Study | Who was followed | What happened |
|---|---|---|
| Systematic review of 14 studies[3] | Clinic patients with IBS, followed for months to years | 2–18% got worse, about 30–50% were unchanged, and the rest improved or their symptoms disappeared |
| Minnesota community study[4] | 1,365 residents surveyed over an average of 12 years | Of people with functional gut symptoms such as IBS at the start, about 40% had none at follow-up, 20% had the same symptoms and 40% had different ones |
| UK 12-month study[5] | 452 adults who met the Rome IV criteria for IBS | 29% no longer met the IBS criteria a year later and had moved to a different functional bowel disorder |
Two cautions. First, "better" often means changed rather than gone. In the Minnesota study, many people whose IBS symptoms disappeared developed other gut symptoms instead, and the overall share of people with IBS stayed stable because new cases kept appearing.[4] Second, steady worsening is the exception.[3] If your symptoms keep getting worse, or new ones appear, see your doctor rather than assuming it's your IBS.
Does IBS that started after a stomach bug fade?
Post-infection IBS, which starts after a bout of gastroenteritis, tends to ease slowly:
- After a contaminated-water outbreak in Walkerton, Canada, IBS affected 28.3% of people who'd had gastroenteritis at 2–3 years, falling to 15.4% at 8 years. That was still more common than in people who hadn't been ill.[6]
- After a Shigella outbreak at a South Korean hospital, infected staff had a clearly higher IBS risk at 1 and 3 years, but by 10 years they were no more likely to have IBS than uninfected colleagues.[7]
- In a smaller UK study, 6 of 14 people (43%) with post-infection IBS had recovered after six years.[8]
What makes improvement more likely?
Researchers can't yet reliably predict who will recover,[1] but psychological factors keep turning up:
- Anxiety and depression. Higher anxiety or depression scores at the start predicted worsening symptoms in the systematic review.[3] In the UK post-infection study, only 1 of 8 people with a history of anxiety or depression recovered, compared with 9 of 19 without, though the numbers were too small to be conclusive.[8]
- Ongoing stress. Among 117 outpatients followed for 16 months, no one facing even one chronic, highly threatening life stress improved by 50%. Everyone who improved did so without such a stressor.[9]
These are things you can work on. Gut-directed psychological therapies don't treat IBS as "all in your head"; they target the gut–brain communication that drives symptoms, and UK guidelines give them a strong recommendation.[1]
Which treatments give lasting relief?
No treatment has been shown to cure IBS, but several can keep symptoms down for years:
- Gut-directed hypnotherapy. In a UK follow-up of 204 patients, 71% responded to treatment, and 81% of those kept their improvement, with benefits lasting at least five years. There was no comparison group in this study.[10]
- A low-FODMAP diet done in full. After restriction and then reintroduction guided by a dietitian, 57% of 103 patients had satisfactory symptom relief at long-term follow-up, compared with 12% before they started.[11] See how the low-FODMAP diet works.
- Treatments matched to your main symptoms, such as soluble fiber, peppermint oil, low-dose tricyclic antidepressants and medicines for IBS with constipation or diarrhea.[1][12] The options are compared in How is IBS treated?
How can you tell whether your IBS is improving?
Because IBS fluctuates, one good or bad week tells you little. A repeatable score works better. The IBS Symptom Severity Score (IBS-SSS) rates pain, distension, bowel habits and quality of life out of 500. A fall of 50 points reliably signals improvement, and scores below 75 are in the range researchers treat as remission.[13] Score yourself on a fixed schedule, not only on bad days. IBS Clue includes the IBS-SSS with weekly re-checks, so you can follow the trend over months instead of relying on memory.
When to see a doctor
See a doctor if you've never been diagnosed, or if your usual pattern changes. These symptoms aren't explained by IBS and need checking:[14][12]
- blood in your stool, or black, tarry stools
- unintentional weight loss
- anemia
- fever, or symptoms that wake you at night
- a family history of bowel cancer, inflammatory bowel disease (IBD) or celiac disease
- symptoms that start after about age 50, when IBS becomes less common[15]
The full list, and the tests doctors use, are in IBS red flags.