Your healthcare provided will be able to diagnose if you have IBS from your symptoms. They will confirm this by doing some medical test and also to make sure that you do not have any other diseases that may cause similar symptoms.
It is very difficult to diagnose IBS. To diagnose IBS, your healthcare provider would first do a combination of your family history, physical examination and used a selected test to help to diagnose IBS. Some of these tests may include:
Imaging studies such as a CT scan
Small intestine x-rays
A lower GI (gastrointestinal) endoscopy (colonoscopy). An endoscopy is a procedure done while the patient is under conscious sedation. It involves inserting a flexible tube with a tiny camera in one end into the GI.