Yes. Before I was diagnosed with IBS, I had a colonoscopy and upper endoscopy. I was given a breath test to check for small intestine bacterial overgrowth. I was also checked for H-pylori. Fortunately, all of those turned out well. I had a sitz marker test which showed slow colonic function (constipation) and later a nuclear medicine test that showed the opposite (diarrhea). There was also a bunch of tests to determine the muscle and nerve functions of the pelvic floor and bowel.
With each test, I held hope of finding answers and possible treatment options, so I could get back to living without fear of debilitating symptoms and humiliating "accidents." I still don't have definitive answers. I have tried many ways to manage my condition, but I have not had much success. It is frustrating.
For me, the worst part of IBS is that it is often unpredictable and intermittent. Sure, there are things I can predict might set off a flare, but there are many times that I am surprised by a flare up and clueless as to what caused it. I can never know how long one is going to last. Sometimes when I am certain my colon must finally be empty, I'm proven wrong and have to make a mad dash to the nearest bathroom--hoping I make it on time. That is harder for me than the intense pain and nausea.