Is that here in Indianapolis?
I'd personally ask both your pediatrician and also make a call to the GI specialist's office just to be sure you're not giving an incorrect dosage or anything else that could compromise their ability to properly diagnose what's causing her issues.
Since you're having a tough time getting in, I'd ask if there are other pediatric GI Specialists you may also try to get opinions from. I had a similar situation personally when needing to make a quick decision on a treatment for cancer. When I told them the urgency of the situation, they were able to get me in much more quickly. Not always the case in busy offices, but you never know when there may be another physician at another facility.
Here, we now have both Riley and the Peyton Manning Children's hospitals. I'm sure there are several options in the Chicago area as well if you're willing to travel there, too.