Irritable bowel syndrome (IBS)


  • Irritable bowel syndrome (IBS) is a common condition that affects the digestive system.
  • It causes symptoms like stomach cramps, bloating, diarrhoea and constipation. These tend to come and go over time, and can last for days, weeks or months at a time.
  • It's usually a lifelong problem. It can be very frustrating to live with and can have a big impact on your everyday life.
  • There's no cure, but diet changes and medicines can often help control the symptoms.
  • The exact cause is unknown – it's been linked to things like food passing through your gut too quickly or too slowly, oversensitive nerves in your gut, stress and a family history of IBS.


Common irritable bowel syndrome (IBS) symptoms

The main symptoms of IBS are:

  • stomach pain or cramps - usually worse after eating and better after doing a poo
  • bloating - your tummy may feel uncomfortably full and swollen
  • diarrhoea - you may have watery poo and sometimes need to poo suddenly
  • constipation - you may strain when pooing and feel like you can't empty your bowels fully

There may be days when your symptoms are better and days when they're worse (flare-ups).  They may be triggered by food or drink.

What can trigger IBS symptoms

IBS flare-ups can happen for no obvious reason.

Sometimes they have a trigger like:

  • alcohol
  • caffeine
  • certain foods, such as spicy or fatty food
  • stress and anxiety

Other symptoms of IBS

IBS can also cause:

  • farting (flatulence)
  • passing mucus from your bottom
  • tiredness and lack of energy
  • feeling sick (nausea)
  • backache
  • problems peeing - like needing to pee often, sudden urges to pee, and feeling like you can't fully empty your bladder
  • not always being able to control when you poo (bowel incontinence)

See a GP if you think you might have IBS

They can check for IBS and do some tests to rule out other problems.

Ask for an urgent appointment if you have:

  • lost a lot of weight for no reason
  • bleeding from your bottom or bloody diarrhoea
  • a hard lump or swelling in your tummy
  • shortness of breath, noticeable heartbeats (palpitations) and pale skin

These could be signs of something more serious.


What happens at your GP appointment

Your GP will ask about your symptoms, such as:

  • what symptoms you have
  • if they come and go
  • how often you get them
  • when you get them (for example, after eating certain foods)
  • how long you've had them for

Before your appointment, it might help to write down details of your symptoms to help you remember them.

Your GP may also feel your tummy to check for lumps or swelling.

Tests for IBS

There's no test for IBS, but you might need some tests to rule out other possible causes of your symptoms.

Your GP may arrange:

  • a blood test to check for problems like coeliac disease
  • tests on a sample of your poo to check for infections and inflammatory bowel disease (IBD)

You will not usually need further tests in hospital unless the GP is not sure what the problem is.

What happens if you're diagnosed with IBS

If the GP thinks you have IBS, they'll talk to you about what it is and what the treatment options are.

It mught be difficult to take in everything they tell you.

If you're unsure about something afterwards, write down any questions you have and make another appointment to go over them.

The IBS network has more information on IBS.


Diet, lifestyle and medicines

There's no single diet or medicine that works for everyone with IBS.  But there are lots of things that can help if you have been diagnosed with it.

General tips to releive IBS symptoms


  • cook homemade meals using fresh ingredients when you can
  • keep a diary of what you eat and any symptoms you get - try to avoid things that trigger your IBS
  • try to find ways to relax
  • get plenty of exercise
  • try probiotics for a month to see if they help


  • do not delay or skip meals
  • do not eat too quickly
  • do not eats lots of fatty, spicy or processed foods
  • do not eat more than 3 portions of fresh fruit a day (a portion is 80g)
  • do not drink more than 3 cups of tea or coffee a day
  • do not drink lots of alcohol or fizzy drinks

*You can buy a card or key from The IBS Network shop or Disability Rights UK shop that can help you access public toilets if you get symptoms while away from home.

How to ease bloating, cramps and farting

  • eats oats (such as porridge) regularly
  • eat up to 1 tablespoon of linseeds a day
  • avoid foods that are hard to digest - like cabbage, broccoli, cauliflower, brussles sprouts, beans, onions and dried fruit
  • avoid products containing a sweetner called sorbitol
  • ask a pharmacist about medicines that can help, like Buscopan or peppermint oil

How to reduce diarrhoea

  • cut down on high-fibre foods, like wholegrain foods (such as brown bread and brown rice), nuts and seeds
  • avoid products containing a sweetener called sorbitol
  • ask a pharmacist about medicines that can help, like Imodium (loperamide)


If you keep getting diarrhoea, make sure you drink plenty of water to avoid dyhydration.

How to relieve constipation

  • drink plenty of water to help make your poo softer
  • increase how much soluble fibre you eat - good foods include oats, pulses, carrots, peeled potates and linseeds
  • ask a pharmacist about medicines that can help (laxatives), like Fybogel or Celevac

Find out more

The IBS Network: diet and IBS

The IBS Network: IBS medicines

See a GP if:

  • diet changes and pharmacy medicines are not helping
  • you need to avoid lots of different foods to control your symptoms

They may refer you to a dietitian or specialist for advice and cal also suggest other treatments to try.

Getting help

Seeing a dietitian for irritable bowel syndrome  (IBS)

A GP may refer you to an NHS dietitian if general diet tips for IBS, such as avoiding foods that trigger your symptoms, are not helping.

They can suggest other changes you can make to your diet to ease your symptoms.

Low FODMAP diet

A dietitian may recommend a diet called a low FODMAP diet.

This involves avoiding foods that are not easily broken down by the gut, such as some types of:

  • fruit and vegetables
  • milk
  • wheat products

Private dietitians

If you want to see a dietitian privately, make sure they're registered with the British Dietetic Association (BDA).

Find a BDA-registered dietitian

IBS medicines from a GP

If pharmacy medicines are not helping, your GP may prescribe a stonger medicine such as:

  • amitriptyline
  • citalopram

These are antidepressants, but they can also help ease IBS symptoms.

They may take a few weeks to start working and can cause side effects.

A GP may refer you to a specialist if you have severe symptoms and other medicines have not helped.

Psychological therapy for IBS

If you have had IBS for a long time and other treatments are not helping, a GP may refer you for a talking therapy such as cognitive behavioural therapy (CBT).

This can help if stress or anxiety is triggering  your symptoms.  It can also help you cope with your condition better.

You can also refer yourself directly to an NHS talking therapies service without a referral from a GP.

These offer therapies like CBT for common mental health problems like stress, anxiety and depression.

Support from the IBS Network

The IBS Network is the national charity for people with IBS. It provides information and advice about living with IBS and offers an online forum.


The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website
Last Updated: 13/10/2023 14:28:45