Diagnosis of Irritable Bowel Syndrome
How do doctors diagnose IBS?
Your doctor may be able to diagnose irritable bowel syndrome (IBS) based on a review of your medical history, symptoms, and physical exam. Your doctor may also order tests.
To diagnose IBS, your doctor will take a complete medical history and perform a physical exam.
The medical history will include questions about
- your symptoms
- family history of gastrointestinal (GI) tract disorders
- recent infections
- stressful events related to the start of your symptoms
Your doctor will look for a certain pattern in your symptoms. Your doctor may diagnose IBS if
- your symptoms started at least 6 months ago
- you’ve had pain or discomfort in your abdomen at least three times a month for the past 3 months
- your abdominal pain or discomfort has two or three of the following features:
During a physical exam, your doctor usually
- checks for abdominal bloating
- listens to sounds within your abdomen using a stethoscope
- taps on your abdomen checking for tenderness or pain
What tests do doctors use to diagnose IBS?
In most cases, doctors don’t need to perform tests to diagnose IBS. Your doctor may perform a blood test to check for other conditions or problems. Your doctor may perform more tests based on the results of the blood test and if you have
- a family history of celiac disease, colon cancer, or inflammatory bowel disease
- a fever
- bleeding from your rectum
- weight loss
Doctors use blood tests to check for conditions or problems other than IBS. A health care professional sends your blood sample to a lab.
A stool test is the analysis of a sample of stool. Your doctor will give you a container for catching and holding a stool sample. You will receive instructions on where to send or take the kit for analysis, to check for blood or parasites. Your doctor may also check for blood in your stool by examining your rectum during your physical exam.
Colonoscopy can show irritated or swollen tissue, ulcers, polyps, and cancer. A trained specialist performs this procedure.
Lower GI series
During a lower GI series, you’ll be asked to lie on a table while the doctor inserts a flexible tube into your anus. The doctor will fill your large intestine with barium. You may be asked to change positions several times during the test.
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.