IBS in pregnancy. Safe ways to ease symptoms

About 1 in 3 pregnant women get constipated, according to a 2024 review of 13 studies from around the world. If you already live with IBS, that number may not surprise you. Pregnancy changes your hormones, your gut bacteria and even how fast food moves through you.

IBS in pregnancy is common, yet it has very little research behind it. In this guide I share what the studies do show, which remedies have the best safety record, and the warning signs that need a doctor. Please use it alongside your midwife or doctor, never instead of them.

What happens to IBS in pregnancy?

IBS in pregnancy can get better, worse or simply change, and no one can predict which way it will go for you. A 2026 review on gut symptoms in pregnancy said there is a lack of good studies on IBS in pregnant women.

What we do know is that pregnancy affects the whole gut. The same review explains that hormones from the placenta and your own body act on the bowel. Nausea and heartburn are the most common gut symptoms, followed by constipation and piles.

The good news from that review is that most of these symptoms settle back to how they were before pregnancy after the birth.

Why does pregnancy make constipation and bloating worse?

Pregnancy hormones slow down the movement of your gut, so stool stays in the bowel longer and gets harder. The AGA also lists the physical changes of pregnancy and some medicines, such as iron tablets, as causes.

The 2024 review found constipation in 32.4% of pregnant women overall. It was least common in the first trimester (21.1%) and most common in the second (34%). A 2026 study of 381 women in Iran found a different pattern, with the most constipation early on. So your own timing may vary.

Iron supplements matter here too. A 2025 Oxford review notes that iron can cause nausea, constipation and diarrhoea. Please do not stop iron your doctor prescribed. Ask instead whether a different form, dose or timing could suit your gut better.

Is IBS dangerous for my baby?

IBS does not damage your baby directly, but studies suggest it is worth good prenatal care. The research shows links, not proof.

A large 2012 study used UK health records and included 26,543 women who had IBS before pregnancy. Women with IBS had a moderately higher risk of miscarriage (about 21% higher odds) and ectopic pregnancy (about 28% higher odds). There was no link with pre-eclampsia or stillbirth.

A 2026 US study looked at about 2 million birth hospital stays. IBS was not linked with major complications or death in mothers. It was linked with longer hospital stays and some placenta problems. The authors felt IBS was more a marker of a complex pregnancy than a strong cause of harm on its own.

Both studies used records, so they cannot show that IBS itself causes these problems. Other health issues, stress and medicines may play a part. My advice is simple. Tell your midwife or doctor about your IBS at your first visit, so they can support you from the start.

How does pregnancy change your gut bacteria?

Your gut bacteria change a lot during pregnancy, and I strongly believe this is part of why your gut can feel so different. In a 2012 study in Cell, researchers tracked 91 pregnant women.

From the first to the third trimester, the gut microbiome changed dramatically. Bacterial richness went down, and some groups, such as Proteobacteria and Actinobacteria, went up. The third-trimester bacteria showed more signs of inflammation.

That sounds worrying, but the researchers think these shifts may help the body store energy for the baby. In other words, a changing gut is normal in pregnancy. What you can do is feed your gut bacteria well with fibre, plants and fluids. My guide to the gut-brain axis explains how your gut talks to the rest of your body.

Is the low FODMAP diet safe in pregnancy?

There are no studies of the low FODMAP diet in pregnancy, so I do not recommend a strict elimination diet while you are pregnant. Your baby needs a wide range of foods, and the 2026 review stresses close watch on the nutrition of mother and baby.

A strict diet can also make it harder to gain enough weight. The NHS says most pregnant women gain 10 to 12.5 kg (22 to 28 lb), mostly after week 20. Gaining too little can raise the risk of an early birth and a small baby.

A gentler approach works better. Keep a short food and symptom diary and limit only the 1 or 2 foods that clearly upset you. If you already know your triggers from the low FODMAP diet phases, use that knowledge without cutting whole food groups. Work with a dietitian if you need to change more than that.

What is safe for IBS constipation in pregnancy?

Food and fibre come first, and some laxatives have a good safety record. The American Gastroenterological Association (AGA) 2024 update lists dietary fibre, lactulose and polyethylene glycol (PEG) as treatment options for constipation in pregnancy.

In the 2026 Iranian study, women who ate more fibre and drank more fluid had lower odds of constipation. A 2015 Cochrane review found only small trials. In one trial of 40 women, a fibre supplement gave about 2 more bowel movements a week than no treatment.

For laxatives, a 2024 trial in Malaysia compared PEG with lactulose in 247 pregnant women who finished the study. Both worked well. About 86% on PEG and 83% on lactulose had a complete bowel movement, and PEG caused fewer loose stools.

Try these steps for constipation.

1. Add fibre slowly. Oats, kiwi fruit, chia seeds and wholegrain bread are good options. Increase over 1 to 2 weeks to limit gas.
2. Ask about psyllium. It is a gentle, bulk-forming fibre. My guide to psyllium for IBS shows how to start low and build up.
3. Drink steadily through the day. Fibre needs water to soften stool.
4. Keep moving. Walking and gentle pregnancy exercise can help your mood and comfort, even though the 2026 study found no clear link with constipation.
5. Use a footstool on the toilet. Raising your knees can make it easier to pass stool without straining.
6. Ask your doctor before any laxative. They can choose one that suits your stage of pregnancy.

For more ideas, see my full guide to IBS with constipation.

What about IBS diarrhoea in pregnancy?

Diarrhoea in pregnancy needs more care, because it can dehydrate you and some medicines have less safety data. Always check with your doctor before taking anything.

Loperamide is a common diarrhoea medicine. A 2008 Swedish study of birth records found a small rise in birth defects when it was used in early pregnancy. The authors said this needs checking in other large studies, so it is not proof of harm. Still, it is a reason to ask first.

Food steps can help with diarrhoea. Eat smaller, regular meals, limit very fatty or spicy food and sip fluids often. My guide to the IBS diarrhoea diet has more tips that are gentle enough for pregnancy.

Are probiotics and peppermint oil safe in pregnancy?

Probiotics looked safe in a 2026 trial, but they did not ease constipation. The trial included 122 pregnant women in China. After 8 weeks, about 23% responded on probiotics and about 21% on placebo, which was not a real difference. No serious side effects were seen.

Peppermint oil and herbal remedies, including Ayurvedic herbs, have very little safety data in pregnancy. A 2026 study of a global health database found that 45% of pregnant women with IBS or indigestion received medicines with limited pregnancy safety data. The authors called for more research on safe treatments. Please check every supplement and herbal remedy with your doctor or pharmacist first.

How can I calm my gut and stress in pregnancy?

Calming your nervous system is safe in pregnancy, and it can ease IBS. The gut and brain talk all the time, so worry can make your gut more sensitive.

Try slow breathing for a few minutes, 2 or 3 times a day. My free Breathe With Me game guides you through it. If anxiety is a big part of your IBS, read my guide to IBS and anxiety. Please also tell your midwife if your mood feels low, because support is available.

When should I see a doctor?

See a doctor or midwife quickly if you have blood in your stool, black stools, a fever or severe belly pain. Severe pain in early pregnancy needs urgent care, because it can be a sign of an ectopic pregnancy.

Also get help if you vomit so much that you cannot keep food or drinks down. The AGA advises early treatment for pregnancy nausea, because it may stop it getting worse. Diarrhoea that does not settle, or signs of dehydration such as dark urine or dizziness, also need a check.

Frequently asked questions

Does IBS get worse in pregnancy?

It can, but it can also improve or stay the same. There are very few good studies on IBS in pregnancy. Pregnancy hormones slow the gut, so constipation and bloating often increase, and most symptoms return to how they were before pregnancy after the birth.

Can IBS cause a miscarriage?

There is no proof that IBS causes miscarriage. A 2012 UK study found a moderately higher risk of miscarriage in women with IBS. It used health records, so it could not show cause and effect. Tell your midwife or doctor about your IBS early so they can support you.

What laxative is safe for IBS in pregnancy?

The AGA lists fibre, lactulose and polyethylene glycol (PEG) as options for constipation in pregnancy. A 2024 trial found PEG and lactulose worked equally well, with fewer loose stools on PEG. Always ask your doctor or pharmacist before you take any laxative.

Can I do the low FODMAP diet while pregnant?

A strict low FODMAP diet has not been studied in pregnancy, and it can make it harder to eat a varied diet. Limit only the 1 or 2 foods that clearly upset you, and work with a dietitian before you cut more.

What I want you to remember

IBS in pregnancy is common and usually manageable. Your hormones and gut bacteria change, so your gut may behave differently for a while. Start with gentle fibre, fluids, regular meals and calm breathing, and ask before any medicine or herb.

Tell your care team about your IBS early, and never ignore the warning signs above. For more gut-friendly habits, read my complete IBS diet guide and join my free 30-Day Calm Gut Challenge. If your gut changes again later in life, my guide to IBS and menopause explains why.