While there are many risk factors triggering the onset of symptoms, the exact reason is still unknown. It is found that even certain food can trigger IBS symptoms. A few triggers are:
- Abnormal movements of the colon and small intestines (too fast or slow, or too strong)
- Hypersensitivity to pain from a full bowel or gas
- Food sensitivities, possibly caused by poor absorption of sugars or acids in food
- Gastroenteritis (“stomachflu” or “stomach bug”), a viral or bacterial infection of the stomach and intestines, may trigger IBS symptoms
- Psychological conditions such as anxiety or depression are observed in many people with IBS, though these conditions have not been found to be a direct cause of IBS.
- Reproductive hormones or neurotransmitters may be off-balance in people with IBS.
- Small intestinal bacterial overgrowth (SIBO)
- Genetics is thought to be a possible cause of IBS, but so far this hereditary link has not been proven.