my son (6) is very self conscious about his height

My son is 6 and is really small for his age, like really small. He had a lot of health issues at an early age and just isn't growing like most kids. We have had tests ran and other than maybe not getting all nutrients when his pancreas was damage, he has no known issues they could find. When people see them they assume 4 at the oldest.A lot of kids at school call him tiny, small, little etc and he said he doesn't like school this year because if it. I have told him to let the teacher know and the students it bothers him but he said they keep doing it. Those comments also bother me when I am out and someone will ask how old and when I tell them of course the first thing they say is "wow, he is so tiny" umm, don't you think we know that and don't you realize he has ears and can hear you? I feel like that isn't frowned upon but if I saw an overweight child and told their parents, wow your kid is really fat for their age, all hell would break lose. Funny thing is, people can't do anything about their height, at least someone who is overweight can lose weight, by the way I would never make a comment like that.I am rambling here, but I have almost said something to others when they bring up his height. I just don't know what else to do to have him not care and do I say anything when others mention how small he is right in front of him. I know he notices and it really bothers me when people point it out. I don't let him notice and if I knew he wasn't self conscious about his size, I may not care as much but knowing he is, it gets to me as well.Thoughts? via /r/Parenting http://ift.tt/2wPy4YU