Information for the public

Diagnosing irritable bowel syndrome

First step: your symptoms

There are no specific tests to confirm irritable bowel syndrome. Instead your doctor should ask you about your symptoms to help make a diagnosis. Symptoms of irritable bowel syndrome can vary widely and also change over time, so your doctor should encourage you to describe all your symptoms and how they affect your daily life before asking you any specific questions.

You should be asked if you have had any of the following symptoms that have lasted for at least 6 months:

  • changes in your bowel habit (for example, diarrhoea or constipation)

  • pain or discomfort in your abdomen

  • a bloated feeling.

If you have had any of these, your doctor should consider assessing you for irritable bowel syndrome. He or she should explain that some specific symptoms need to be present for a positive diagnosis. These are either:

  • abdominal pain or discomfort that goes away when you empty your bowel


  • abdominal pain or discomfort with a change in how often you empty your bowel or stools (faeces or poo) that look different from usual.

You also need to have 2 of the following symptoms:

  • a change in how you pass stools – for example, needing to strain, feeling a sense of 'urgency' or feeling that you haven't completely emptied your bowel

  • bloating, tension or hardness in your abdomen

  • a feeling that your symptoms are worse after eating

  • passing of mucus from the rectum.

If you have abdominal pain or discomfort, your doctor should ask if the pain is in one area or if it moves around your abdomen. This is because in irritable bowel syndrome the pain does not usually stay in one place. As part of your changing bowel habit you may experience faecal incontinence, which means having accidents that involve a leakage of faeces. You may also have symptoms such as tiredness, nausea, backache and bladder problems (such as passing urine frequently or experiencing a sense of urgency). Your doctor should ask if you have had any of these symptoms to help confirm your diagnosis.

Next step: ruling out other problems

If your doctor thinks you may have irritable bowel syndrome you should be offered some blood tests. These will allow the doctor to check for anaemia and general levels of inflammation in your body, and make sure that you do not have another gut disorder called coeliac disease.

Your doctor should explain how the tests will be done and where they will take place, and also answer any questions you have.

The following types of tests are not necessary to help diagnose irritable bowel syndrome:

  • ultrasound

  • rigid or flexible sigmoidoscopy

  • colonoscopy or barium enema

  • thyroid function test

  • faecal ova and parasite test

  • faecal occult blood test

  • hydrogen breath test.

Referral to a specialist

When you first describe your symptoms, your doctor should explain that it is important to rule out the possibility that they are being caused by other illnesses that need specialist treatment, such as cancer or inflammatory bowel disease (IBD). You should be asked if you have, or have had, any of the following:

  • unintentional and unexplained weight loss

  • bleeding from the rectum

  • a family history of bowel or ovarian cancer.

If you are aged 60 or over, your doctor should also ask if you have had a change in your bowel habit that has lasted for more than 6 weeks in which you are producing looser stools or need to empty your bowel more frequently.

Your doctor may suggest a physical examination of your abdomen or rectum to check for lumps. Before you agree to these examinations, the doctor should explain exactly what will happen, and why.

Some symptoms of irritable bowel syndrome are similar to those that could be experienced by women with ovarian cancer (for example, bloating or pain in the abdomen). NICE has produced advice about recognition and initial management of ovarian cancer that explains when women should be offered tests to check for ovarian cancer.

Depending on your symptoms and the results of your blood tests and examinations, your doctor may refer you to a specialist for further tests. Your doctor should explain that being referred does not necessarily mean you have cancer or IBD, but that it should be ruled out. NICE has produced advice about being referred for suspected cancer.

Questions to ask about tests

  • Please give me more details about the tests I have been offered.

  • How long will it take to get the results?

  • Can you tell me more about tests to check for ovarian cancer?

  • Please give me more information about why I have been referred to a specialist.

  • If I am not being offered any further tests, could you explain why?