Irritable bowel syndrome (IBS) is a common disorder in which your bowels do not work properly. It can cause symptoms such as pain, bloating, constipation and diarrhoea.
We do not know exactly what causes IBS. But it seems to be related to your bowel being more sensitive than usual, and food passing through your digestive system too quickly or too slowly.
IBS is very common and affects around 1 in 7 people. It is more common in women than men and in people under the age of 50.
IBS does not increase your chance of getting other bowel diseases, such as bowel cancer.
Symptoms of irritable bowel syndrome
The most common symptoms of IBS are:
pain or discomfort in your stomach
bloating or swelling in your stomach
diarrhoea (the runs) or constipation (hard poo) or sometimes both
passing mucus with your poo
too much wind (flatulence or farting).
Your symptoms can come and go and can last for a few days or up to a few months. They often happen when you are feeling stressed or after you have eaten certain foods. They may often settle down for a long time.
Diagnosing irritable bowel syndrome
A doctor can usually diagnose IBS based on your symptoms.
Your doctor may examine you, ask you about your symptoms and discuss your family history and overall health and lifestyle. Other conditions, such as coeliac disease and inflammatory bowel disease can have similar symptoms to IBS. So, your doctor may ask you to have a blood test and provide a stool (poo) sample to rule them out.
In some cases, your doctor may refer you to have a test such as a colonoscopy or gastroscopy.
Johannesson E., et al. Intervention to increase physical activity in irritable bowel syndrome shows long-term positive effects. World J Gastroenterol 2015 January 14; 21(2): 600-08.
Peters S.L., Yao C.K., Philpott H., Yelland G.W., Muir J.G., Gibson P.R. Randomised clinical trial: the efficacy of gut-directed hypnotherapy is similar to that of the low FODMAP diet for the treatment of irritable bowel syndrome. Alimentary Pharmacology and Therapeutics. 2016. 44(5):447-59.
McKenzie Y.A., Bowyer R.K., et al. British Dietetic Association systematic review and evidenced-based practice guidelines for the dietary management of irritable bowel syndrome in adults (2016 update). J Hum Nutr Diet. 8 Jun 2016 | DOI: 10.1111/jhn.12385.
Image and embedded video sources
FODMAP image from Shutterstock (image ID 1351926128). May 2019.
Image of a couple walking on the hills from Shutterstock (image ID 16049137). June 2016.
Image of a doctor talking to a patient from Shutterstock (image ID 317573612). November 2015.
Image of a glass of water with a fibre supplement from Shutterstock (image ID 1554653579). October 2020.
Image of a woman sitting at a table in front of a window from Shutterstock (image ID 511853110). August 2021.
Video of IBS symptoms and the low FODMAP diet from Monash University on YouTube.