Wrote a huge reply, but it got deleted when I switched chrome tabs by accident.
Yeah, it would be interesting to hear what your doctor says in regards to the l-glutamine supplementation.
Body builders use this stuff to heal soar muscles. So you can usually find it quite easy in most nutritional supplement stores. The one I purchased was from Amazon USA and made by Jarrows. After going through quite a bit of supplements based on online suggestions I’ve found Jarrows stuff to be quite good, so this is why I bought this one. There are other options here in Canada, but this one was the best value.
From what I read, l-glutamine is made by fermentation of beets. So it seemed quite natural.
If your deciding between pure powder and l-gluteamine pills, I would definitely go with the pure form as it doesn’t/shouldn’t contain any fillers. Let me know which one you end up getting.
Hope that helps and look forward to any updates.