Irritable bowel syndrome

What is irritable bowel syndrome (IBS)?

Irritable bowel syndrome (IBS) is a common long-term disorder of how the gut works, causing abdominal pain, bloating and diarrhoea, constipation or both. The bowel looks normal on testing and is not damaged. Symptoms come and go, often with stress, certain foods or after a bowel infection.

In IBS, the way the gut moves and sends signals is altered, and the brain-gut connection plays a part. Routine tests are often normal.

What causes irritable bowel syndrome?

IBS has no single cause. The gut is overly sensitive and moves in an altered way, and the connection between the brain and gut is involved. Stress, a previous bowel infection, certain foods and changes in gut bacteria can trigger or worsen symptoms. IBS does not cause bowel cancer.

• Heightened sensitivity of the bowel
• Altered gut movement
• Stress and the brain-gut axis
• A previous bowel infection
• Food triggers and changes in gut bacteria

What are the symptoms?

IBS typically causes abdominal pain linked to opening the bowels, along with bloating, wind, and diarrhoea, constipation or both. The pain often eases after a bowel movement. Some people notice mucus in the stool. Symptoms vary between people and come and go over time.

• Abdominal pain linked to bowel movements
• Bloating and wind
• Diarrhoea, constipation, or both
• Mucus in the stool
• Symptoms that improve after opening the bowels

When should I see a colorectal surgeon?

See a doctor if IBS-type symptoms are new, last more than a few weeks, or begin from age 50. Blood in the stool, unexplained weight loss, fever, symptoms that wake you at night, or a family history of bowel cancer are not typical of IBS and need prompt assessment.

The warning signs below need prompt attention.

• Blood in the stool
• Weight loss or fever
• Symptoms starting later in life
• Night symptoms that wake you
• A family history of bowel cancer

How is it diagnosed?

IBS is diagnosed from a typical pattern of symptoms after other conditions are excluded. This usually means a symptom history, an examination, and blood and stool tests, including a check for coeliac disease. A colonoscopy is arranged when warning signs are present, or when your age or family history calls for it.

• A careful symptom history
• Blood and stool tests
• Colonoscopy when warning signs or age suggest it
• Exclusion of coeliac disease and inflammatory bowel disease

How is irritable bowel syndrome treated?

IBS is treated with changes to diet and lifestyle, such as adjusting fibre, finding trigger foods and keeping regular meals, plus medicines for diarrhoea, constipation or pain as needed. Stress management and sleep help, and some people benefit from a dietitian-led diet. Surgery has no role in IBS.

• Diet changes and identifying trigger foods
• Soluble fibre and plenty of water
• Medicines for diarrhoea, constipation, or pain
• Stress management and sleep
• Gut-directed approaches in some cases

What are the risks?

IBS does not cause cancer or permanent damage to the bowel. The main risk is that a different condition, such as coeliac disease, inflammatory bowel disease or bowel cancer, is mistaken for IBS, which is why tests are done. Some medicines used for IBS can cause side effects.

• IBS itself does not cause cancer or permanent damage
• The main risk is missing a different condition that mimics it
• Some medicines can cause side effects