Because IBS has no single cause, there's no single cure, so treatment aims to calm the symptoms that bother you most. US (ACG) and UK (BSG) guidelines grade each option by the strength of the evidence, and both choose treatment by your main symptoms and IBS subtype: IBS with constipation (IBS-C), with diarrhea (IBS-D) or mixed.[1][2] Most plans start simple and add steps only if needed.
What is the first step in treating IBS?
- A clear diagnosis and explanation. UK guidelines strongly recommend explaining IBS as a disorder of gut–brain interaction, including how diet, stress and past infections affect it. A good relationship with your doctor can itself improve symptoms and quality of life.[1]
- Regular exercise, advised for everyone with IBS.[1] In a Swedish trial, people coached to be more active improved their IBS Symptom Severity Score by 51 points, compared with 5 points in the control group.[3]
- First-line diet advice: regular meals, adequate nutrition, limiting alcohol and caffeine, adjusting fiber and cutting down on fatty and spicy foods. This advice rests mainly on clinical experience rather than trials.[1]
- Soluble fiber such as psyllium (ispaghula), which both guidelines strongly recommend. Start low and build up slowly to limit bloating, and avoid insoluble wheat bran, which can make symptoms worse.[1][2] In a primary-care trial, 57% of people responded to psyllium in the first month, compared with 35% on placebo.[4]
When should you try the low-FODMAP diet?
When first-line advice isn't enough. FODMAPs (fermentable oligo-, di-, monosaccharides and polyols) are carbohydrates that draw water into the small intestine and produce gas in the colon.[1] In a network meta-analysis of 13 trials, the low-FODMAP diet ranked first among the diets compared for overall symptoms, pain and bloating.[5] UK guidelines recommend it as a second-line diet supervised by a trained dietitian, with FODMAPs reintroduced according to tolerance, and advise screening out people at risk of overly restrictive eating first. US guidelines suggest a limited trial.[1][2] If you're pregnant, or it's for a child, talk to a doctor before changing your diet. See the low-FODMAP diet.
Which medicines are used for IBS?
Medicines are matched to your main symptom. Availability and brand names differ between countries, and many are prescription-only; ask your doctor or pharmacist about doses and side effects. "Strong" and "weak" or "conditional" describe how confident each guideline panel was.[1][2]
| Main problem | Options | Guideline support |
|---|---|---|
| Overall symptoms and pain | Peppermint oil | ACG: suggested (conditional). BSG: may help (weak) |
| Cramping pain | Antispasmodics, such as hyoscine butylbromide, mebeverine or dicyclomine (dicycloverine) | BSG: certain ones may help (weak). ACG: against those available in the US (conditional) |
| Ongoing overall symptoms and pain | Low-dose tricyclic antidepressants, such as amitriptyline or nortriptyline | ACG: recommended (strong). BSG: second-line (strong) |
| Ongoing overall symptoms | SSRIs used as gut–brain neuromodulators | BSG: may help, second-line (weak) |
| IBS-C | Polyethylene glycol (PEG) laxative | BSG: may help constipation (weak). ACG: not on its own for overall IBS-C symptoms (conditional) |
| IBS-C | Guanylate cyclase-C agonists (linaclotide, plecanatide); chloride channel activator (lubiprostone); tenapanor | ACG: strong for the first two classes. BSG: strong, second-line, for all |
| IBS-D | Loperamide | BSG: may help diarrhea (strong). ACG: not first-line, as it doesn't improve overall symptoms |
| IBS-D | Rifaximin, a gut-acting antibiotic | ACG: recommended (strong). BSG: second-line (weak); not available for IBS in many countries |
| IBS-D | 5-HT3 antagonists (alosetron, ramosetron, ondansetron) | BSG: second-line (weak), likely the most effective class for IBS-D. ACG: alosetron for women with severe IBS-D (conditional) |
| IBS-D | Eluxadoline | ACG: suggested (conditional). BSG: second-line (weak); not suitable after gallbladder removal or with pancreatitis or alcohol dependence |
| Any subtype | Probiotics | ACG: suggests against (conditional). BSG: may help; try for up to 12 weeks and stop if no benefit (weak) |
Peppermint oil beat placebo in a meta-analysis of 10 trials, though side effects were more common and the evidence was of very low quality.[6] See the IBS-D diet and the IBS-C diet for food-based approaches by subtype.
Do antidepressants help IBS?
At low doses, yes, and being prescribed one doesn't mean your doctor thinks you're depressed. Tricyclic antidepressants are used as gut–brain neuromodulators: they are thought to dampen pain signaling between gut and brain, and can slow the gut.[2] The ATLANTIS trial tested low-dose amitriptyline in 463 adults at 55 general practices in England whose symptoms persisted despite diet changes and first-line treatments. After six months, IBS-SSS scores were lower with amitriptyline than with placebo, and the drug was judged safe and well tolerated, although 13% stopped it because of side effects.[7] Across earlier trials, about one extra person improved for every 4 to 5 treated, and drowsiness and dry mouth were the most common side effects.[2]
Do psychological therapies work for IBS?
Yes. IBS-specific cognitive behavioral therapy (CBT) and gut-directed hypnotherapy act on the gut–brain connection. In a network meta-analysis of 41 trials with 4,072 people, both were effective and had the largest evidence base, although the trials' high risk of bias means the benefit may be overestimated.[8] UK guidelines strongly recommend them, to be considered if symptoms haven't improved after 12 months of drug treatment, or earlier if available and you prefer.[1] US guidelines suggest them for overall symptoms.[2] Being offered therapy doesn't mean your symptoms are "all in your head."
How do you know a treatment is working?
Give each change a fair trial, change one thing at a time, and measure the result. Scoring your symptoms with the IBS-SSS before and during a treatment shows whether it's helping more reliably than memory. IBS Clue includes the IBS-SSS with weekly re-checks alongside a meal and symptom log, so you can see what changed and when. IBS symptoms naturally come and go,[1] so judge a treatment over weeks, not days.
Which treatments aren't recommended?
Some widely promoted options aren't supported by the guidelines:
- Elimination diets based on IgG food antibody tests (BSG, strong).[1]
- A gluten-free diet for IBS in general (BSG, weak).[1]
- Fecal microbiota transplant for overall IBS symptoms (ACG, strong).[2]
- Opioid painkillers, unnecessary surgery, and unproven, unregulated tests or treatments promoted for profit (BSG, strong).[1]
When to see a doctor
Get a diagnosis before treating yourself: simple blood tests, and a stool test if you have diarrhea, help rule out celiac disease and IBD.[1] See a doctor promptly for rectal bleeding or black stools, unintentional weight loss, iron-deficiency anemia, symptoms that start at an older age, or a family history of bowel cancer, IBD or celiac disease.[1][2] UK guidelines advise referral to a specialist if the diagnosis is in doubt or symptoms are severe or don't respond to first-line treatment.[1] See IBS red flags.