ND = naturopathic doctor
Yes, your GI *should* know about it. Usually a Biomed or a Naturopath is a bit more versed in the subject though. Ask about Microbiological Stool testing which has to be sent to Doctors Data Labs, the second is an Organic Acid Test (OAT) which is a urine test done by Great Plains Labs. The results from those 2 tests will help give you a clearer picture as to what's really going on in his little tummy.
It took us 4 ND's to find one that was actually well versed in Gut functions
The 4th, which we are seeing now and he is quite good - I found through having completed "DAN" certification (defeat autism now) Here's a list of physicians in the US who have completed the training.
http://www.autismwebsite.com/practitioners/us_lc.htm Again, don't let the whole autism title throw you off or scare you. That's just one symptom that can be a result of severe gut dysbiosis. Most DAN practioners are well versed in matters of Gut health. Just sharing that in case you're looking for another opinion.
When Ds2 first presented with typical gut dysbiosis symptoms (MSPI, severe constapation, severe reflux, mucous stool ect), our regular family Dr was too quick to want to prescribe him hypoallergenic FF, laxitives, zantac ect and I wasn't happy with her ideas. To me, I felt she wanted to mask the symptoms instead of finding the root cause, kwim? That, and there was no way I was going to give up Bf'ing since I believe so strongly in it. So that lead me on a quest through numerous Elimination Diets and naturopaths, until I came across the "GAPS" book and then it all made sense to me. Both my boys have varied degrees of gut dysbiosis, but Ds2 is by far the most severe. We're working on the treatment still, but the improvements have been quite substancial thus far.
Hopefully Eloise will chime in too... I believe she posted earlier on your thread. She too has read the GAPS book and can probably help you as well.