What causes IBS?

Doctors don’t know exactly what causes IBS, and different factors may cause IBS in different people. Genetics may also play a role. But many people with IBS have similar issues in common, and these may contribute to the development of IBS. These include:


  • Stressful or difficult early life events, such as physical or sexual abuse;
  • Certain mental disorders, such as depression, anxiety and somatic symptom disorder;
  • Bacterial infections in your digestive tract;
  • Small intestinal bacterial overgrowth (change in the type of bacteria in the small intestine);
  • Food intolerances or sensitivities (certain foods trigger digestive symptoms).