My first son had the same issues but not as sensitive to dairy. His ears were terrible! He had a cycle of ear infections/antibiotics/diarrhea for 10 months straight!! I fought getting tubes because it sounded so scary to put him under anesthesia.
When my 2nd son was born, he started the same pattern, only at 5 months old!! (way earlier than my oldest) So I decided to do the tubes when he was 10 months old. He was an early walker at 9 months. But he would walk a couple steps and fall down. The day after the surgery when we could let him get around by himself, I nursed him in the morning and put him down and he walked across the room!! I couldn't believe how much his ears affected him.
Every time my boys would start teething, their ears would get infected, they'd be on antibiotics, they'd get diarrhea, I'd start acidopholus, they'd get another toothe, another ear infection, they'd go on another antibiotic, get diarrhea.....It's a vicious cycle!
While it's hard to watch them go under the anesthesia, they're done in literally 7 minutes and they are not in any pain. And the rewards are amazing!!! I would get tubes put into his ears as soon as possible. Then you don't have the added worry of too many antibiotics and his body requiring stronger and stronger doses/kinds to fight off future illnesses.
By the way, my oldest is 7 and just yesterday had another ear infection in the ear that his tube fell out. Some kids just have a hard time with that and both his dad and I still have sensitive ears too.
Hope this helps!