Jeanette, thank you so much for the info. To be honest, I am a bit confused when it comes to fat malabsorption. I thought that D is definitely one of the symptoms, and I always only have C.
I agree with your thoughts about the second doctor. I don't think I'll make him my "new" doctor just because I don't believe he's very knowledgeable in the IBS area (he said other stuff that kind of raised a red flag for me). I just found out that Johns Hopkins has a satellite location in my town (I live close to Baltimore) and they seem to have a pretty good gastroenterology program. So I'll have to check if they take my insurance but if they do I'll probably try to get an appointment there.
Lately I've been thinking that my problems must be somewhat bacteria related. I tried the SCD but it got so painful that I just had to stop. So once I talk to the new GI I'll decide what to do. I'll ask about antibiotics and about the fat test and see what s/he thinks.
Please keep me posted on the test results and what you decide to do about that antibiotic treatment.