E.G. blood tests, stool tests, colonoscopy etc.
I'm in the UK and was written off as having IBS and basically, just told to get on with it. I've got worse and worse; been vomiting and now can no longer keep down much food, have lost weight and recently, 2 close family members have been diagnosed with Crohn's disease. Upon my insistence, I have finally been referred to a gastroenterologist for a colonoscopy etc, it only took 5 years!