Re: 18 months old and 19 lb. Too small?
As long as there wasn't a sudden stop in growth or major decline, I'd say he's probably just small. Was there some kind of change that concerned your doctor? He really doesn't sound extremely small to me. My dd is only about 20 lbs, and she's only 2 months younger. But I'm small, and she's always been small, so my doctor wasn't worried.
I just don't see the need for a GI specialist unless there was some negative change in his growth/eating habits. As long as he's growing and meeting milestones, he sounds healthy to me. Please don't feel like a failure! You're doing great.
Bee- proud mama to Maggie, 6/12/06 and Maya, 10/15/08