Irritable bowel syndrome (IBS) is a chronic disorder of gut-brain interaction. It causes repeated abdominal pain together with changes in bowel movements, which may include diarrhea, constipation or both. IBS can be painful and disruptive, but it does not cause visible damage to the digestive tract.
Common symptoms
- Abdominal pain or cramping, often related to bowel movements
- Diarrhea, constipation or alternating between both
- Bloating and gas
- A feeling that a bowel movement is incomplete
- Mucus in the stool
Diagnosis
There is no single test for IBS. A healthcare professional reviews the pattern and duration of symptoms, medical and family history and performs a physical examination. Blood, stool or other tests may be used when another condition needs to be excluded.
Symptoms such as anemia, rectal bleeding, bloody or black stools, unexplained weight loss or a strong family history of celiac disease, inflammatory bowel disease or colorectal cancer may point to another condition and require further assessment.
If celiac disease is being considered, do not start a gluten-free diet before testing unless a healthcare professional advises you to. Removing gluten beforehand can make diagnostic testing less accurate.
Treatment
Treatment depends on the symptoms and may require trying more than one approach. Options can include dietary changes, physical activity, adequate sleep, medicines and gut-directed psychological therapies.
Some people benefit from increasing soluble fiber. A low-FODMAP diet may help selected people, but it is best used as a structured short-term trial followed by food reintroduction, ideally with guidance from a dietitian familiar with IBS. Medicines may be chosen specifically for diarrhea, constipation or abdominal pain.
Living with IBS
Keeping a short record of meals, bowel movements and symptoms can help identify patterns without creating unnecessary food restrictions. Stress does not mean that IBS is imaginary, but the gut and brain communicate closely, and stress management or therapies such as cognitive behavioral therapy or gut-directed hypnotherapy may improve symptoms in some people.
When to seek medical advice
Arrange medical assessment for new or persistent bowel symptoms, especially if you have not previously been diagnosed with IBS. Seek prompt assessment for rectal bleeding, blood or black stools, unexplained weight loss, anemia, fever, persistent vomiting, a new abdominal mass or symptoms that are rapidly worsening.
Related topics
Sources
Last reviewed: 4 September 2026.
Medical disclaimer: This information is general and does not replace individual medical assessment, diagnosis or treatment.