Yes, I agree - as long as you're seeing your pediatrician and GI in-person regularly, they'll watch your kiddo's height and weight. Sometimes they will do an x-ray of the wrist to check bone age, but in general, first they monitor height and weight and see if your child is following his/her growth curve. For example, my daughter's weight was always around the 10th percentile (from when she was very young) and so when she lost quite a bit of weight and it was well under the 5th percentile, her GI was concerned.