Irritable bowel syndrome (IBS) is a common condition of the digestive system. It can cause bouts of stomach cramps, bloating, diarrhoea and constipation.

Symptoms vary between individuals and affect some people more severely than others. However, most people have either diarrhoea, constipation, or bouts of both. You may also have mucus in your stools.

You may find the painful stomach cramps of IBS ease after going to the toilet and opening your bowels.

What causes IBS?

The cause of IBS is unknown, but several hypotheses have been proposed. The risk of developing IBS increases sixfold after acute gastrointestinal infection. Post-infection, further risk factors are young age, prolonged fever, anxiety, and depression.[21] Publications suggesting the role of brain-gut “axis” appeared in the 1990s, such as the study “Brain-gut response to stress and cholinergic stimulation in IBS” published in the Journal of Clinical Gastroenterology in 1993.[22]A 1997 study published in Gut magazine suggested that IBS was associated with a “derailing of the brain-gut axis.”[23] Psychological factors may be important in the aetiology of IBS.[19]

When to see your GP

Visit your GP if you think you have IBS. They will want to rule out other illnesses, such as an infection, coeliac disease (a digestive condition where a person has an adverse reaction to gluten), or a chronic inflammation of the gut.


The mind-body or brain-gut interactions has been proposed for irritable bowel syndrome and is gaining increasing research attention.[71] For some patients psychological therapies may help with symptoms. Cognitive behavioural therapy and hypnosis have been found to be the most beneficial. Hypnosis can improve mental well-being and cognitive behavioural therapy can provide psychological coping strategies for dealing with distressing symptoms as well as help suppress thoughts and behaviours that increase the symptoms of irritable bowel syndrome.[72][71]Cognitive behavioural therapy has been found to improve symptoms in a number of studies.[101][102] Relaxation therapy has also been found to be helpful.[103]

19. Whitehead WE, Palsson O, Jones KR (2002). “Systematic review of the comorbidity of irritable bowel syndrome with other disorders: what are the causes and implications?”. Gastroenterology122 (4): 1140–56. doi:10.1053/gast.2002.32392. PMID 11910364.

21. Thabane M, Kottachchi DT, Marshall JK (2007). [www3.interscience.wiley.com/cgi-bin/fulltext/117987841/HTMLSTART “Systematic review and meta-analysis: The incidence and prognosis of post-infectious irritable bowel syndrome”]. Aliment Pharmacol Ther26 (4): 535–44. doi:10.1111/j.1365-2036.2007.03399.x. PMID 17661757. www3.interscience.wiley.com/cgi-bin/fulltext/117987841/HTMLSTART.

22. Fukudo S, Nomura T, Muranaka M, Taguchi F (1993). “Brain-gut response to stress and cholinergic stimulation in irritable bowel syndrome. A preliminary study”. J. Clin. Gastroenterol.17 (2): 133–41. doi:10.1097/00004836-199309000-00009. PMID 8031340.

23. Orr WC, Crowell MD, Lin B, Harnish MJ, Chen JD (1997). “Sleep and gastric function in irritable bowel syndrome: derailing the brain-gut axis”. Gut41 (3): 390–3. doi:10.1136/gut.41.3.390. PMC 1891498. PMID 9378397. //www.ncbi.nlm.nih.gov/pmc/articles/PMC1891498/.

71. Shen, YH.; Nahas, R. (Feb 2009). “Complementary and alternative medicine for treatment of irritable bowel syndrome”. Can Fam Physician55 (2): 143–8.PMC 2642499. PMID 19221071. //www.ncbi.nlm.nih.gov/pmc/articles/PMC2642499/.

72. Ducrotté, P. (Nov 2007). “[Irritable bowel syndrome: current treatment options]”. Presse Med36 (11 Pt 2): 1619–26. doi:10.1016/j.lpm.2007.03.008. PMID17490849.

101. Kennedy T, Jones R, Darnley S, Seed P, Wessely S, Chalder T (2005). “Cognitive behaviour therapy in addition to antispasmodic treatment for irritable bowel syndrome in primary care: randomised controlled trial”. BMJ331 (7514): 435. doi:10.1136/bmj.38545.505764.06. PMC 1188111. PMID 16093252.http://bmj.bmjjournals.com/cgi/content/full/331/7514/435.

102. Heymann-Mönnikes I, Arnold R, Florin I, Herda C, Melfsen S, Mönnikes H (2000). “The combination of medical treatment plus multicomponent behavioural therapy is superior to medical treatment alone in the therapy of irritable bowel syndrome”. Am J Gastroenterol95 (4): 981–94. doi:10.1111/j.1572-0241.2000.01937.x. PMID 10763948.

^ 103. van der Veek PP, van Rood YR, Masclee AA (2007). [www3.interscience.wiley.com/cgi-bin/fulltext/117987882/HTMLSTART “Clinical trial: short- and long-term benefit of relaxation training for irritable bowel syndrome”]. Aliment. Pharmacol. Ther.26 (6): 943–52. doi:10.1111/j.1365-2036.2007.03437.x. PMID17767479. www3.interscience.wiley.com/cgi-bin/fulltext/117987882/HTMLSTART.