is this autism

i have a son who was born in march 2008,he is a very active kid,but have a very low appetite and also a picky eater.Recently we traveled to our native and he had diarrhea,the docs there gave him injection.Then the very next day we took him to pediatrician and my son started crying so he said he might have autism.I never doubted that because he is very social,interacts and loves and shares his toys.He started talking quite early around a year he started calling dad and now he makes few words knows his alphabets,numbers,even says that A says apple and so on...we have 3 languages so at times he gets confused and blabbers i am not sure if its normal,at times i understand him but people from outside doesn't.I am just concerned because he doesn't take medcine so i have to always mix with milk is it a behaviour of autistic kid.I raised this to our  pediatrician in US whom my son has been going to but she said she is very positive that he is not autistic.But i am very worried about this.He also gets repeated ear infections especially in the winters. and he does have frequent colds,,should i be concerned,

[Jessica L Thomason Sassi, Ph.D., BCBA-D]

Based on your description, I would say that it doesn’t sound like he meets the diagnostic criteria for autism (delayed social interaction skills, delayed language skills, and highly restricted interests and/or repetitive behavior).  Further, diagnosis requires in-person evaluation by a professional, and it sounds as though your family doctor has done an informal evaluation and isn’t concerned.   Many typically developing children are picky eaters, and many refuse novel or bad-tasting items (such as medicines), so I wouldn’t be overly concerned about that as an indicator of autism.
Good luck to you and your family.