My 7 month old has No interest in solids. We weaned him at 5 months and he was fine then had lryingitis and we found out he has a milk allergy all at the same time. He's now on prescription milk and far happier but won't take solids, and if i do get any porridge or baby rice in him he's not interested in his milk so I'm not really achieving anything. He's a good size baby, 8lb born and now a good 20lb. Should I be concerned?