I was Dx with IBS prior to being Dx with Crohn's. I thought the same thing you did - they just kind of threw that out at me with no "real" testing. Actually, I don't remember them every sending me for anything but a barium swallow but that's because I was having reflux issues. They just based the IBS Dx off my symptoms of having D a lot. Plus, my doctor is a family member and he knows that IBS runs in the family so you know he was just booting me out with an easy Dx!
I can remember being SO sick with D all the time...every time I put food in my mouth, I was in the bathroom with D immediately...and I was going to the bathroom sometimes "just because" throughout the day and in the middle of the night. The D hit fast, too.
And I remember telling girlfriends about my IBS, saying I didn't want to go with them somewhere that day because of this IBS that was really giving me a rough time. And I remember one girl saying, "OMG, get over it! I have IBS, too...what's the big deal? You pull over, hit the bathroom at McDonald's and go on your way!". So I said, "Well, then you and I must have MUCH different forms of IBS because if you had what I had, you wouldn't say it wasn't a big deal!" Oooh, that made me MAD.
Less than a year later I was diagnosed with Crohn's. It all started when I told my family member doctor that I'd been waking up in the middle of the night with D. He was like, "OH! I didn't realize your bowels had been waking you UP! Well, then - we need to send you to a Gastroenterologist."
So off I went to the GI having a small bowel follow through, abdominal CT scan and Colonoscopy. The Crohn's was Dx based primarily on the results of the Colonoscopy and a biopsy done during that. My colon is scattered with deep ulcers and the biopsy showed some kind of "marker" that is usually specific to Crohn's patients.
I have had mild symptoms of Crohn's compared to many people on this board. I've had no real bleeding or fistulas/strictures etc. Everyone is different. I would certainly think Crohn's could be "missed" in a scope. It's my understanding that doctors are simply looking and comparing symptoms that you're having to determine what'cha got. I was tested for Celiac Disease but it came back negative. There's not really a "test" for Crohn's...just markers within the blood and tissue samples that tend to lean toward Crohn's. I might be uninformed about that, though...if so, I'm sure someone will come along and clarify that.
One thing I would specifically ask your doctor to give you is a breath test for SMALL BOWEL BACTERIA OVERGROWTH. I read online yesterday that 67% of patients who are diagnosed with IBS actually have SBBO instead! And it can be cleared up by a simple round of antibiotics. But most doctors find it "easier" to just throw IBS out there if there are no other actual symptoms to explain anything. Google SBBO and read about it and see if it describes you! :) SBBO is also attributable to FATIGUE which would explain your tired, weak, dizzy feelings, too. Just an idea!
Diagnosed in October, 2004 at age 33.
Currently taking Colazal, Nexium, One-A-Day multivitamin, Omega-3 Fish Oil, Vitamin D, Vitamin A
Secondary conditions: mouth ulcers, joint pain, extreme fatigue