Your milk may not agree with him. Or, if you are using formula, the formula may not agree with him. One of my daughters was unable to breastfeed any of her six babies because of a problem with her milk. She had to put them all on formula and they were fine.
I found out that I have to stay away from dairy products and switch to almond milk, he is doing much better now as long as I stay away from lactose.
I'm glad you found a solution. If you have further problems, try going gluten free. Gluten is an increasing problem in the US, having something to do with changes in our wheat processing perhaps. I have a problem with gluten here, but not overseas (where I lived for some time).
I have the same problem. No dairy for me. I'm glad symptoms went away because soy would be the next to go.
I have to burp mine..he takes forever to burp but if he doesnt its terrible and I feel aweful lol but luckily its not real often.
If he gets bad again , get little remedies gas drops. It works wonders. I keep it on hand all the time. And they love the flavor! I tried it and it actually is pretty good .