I need to do something to get him to stop waking up for hourly night feeds.

[TwistTee]

I think it is mainly down to wind. No matter how long I try to wind my 4 mnth old son, nothing comes up and that is despite gripe water/infacol. As a result he doesn't take much in before falling asleep in my arms.
When I put him back in his cot, he struggles a bit to get comfortable and may take 2/3 tries before he will settle, only to wake about an hour later hungry.
I tried a bottle of aptamil formula one night but he woke up covered with an allergic rash. The GP says just to try a different make, but before I do I want to know if it will actually make any difference or if there are other things I can try and avoid the formula till he is 6 months.
Any ideas? I'm a bit desperate.

There is a horrendous sleep regression at 4 months, your dc may not be waking with hunger at all, just having crap sleep. Can dp help at night until things settle down?

Has he always been like this? Could it be the 4 month sleep regression?

No, he was always a pretty good sleeper until recently. 3hrly feeds and occasionally longer. What is the 4 mth regression?

We had hourly wakings for a good week or so as past of four month regression. The slowly the time between wake ups reduced and she was back to longer streatches again.

sounds like four month regression as others have said - lots of threads about it!

but it also sounds like your DS may have a dairy allergy if formula is giving him a rash - something to watch out for when you wean him onto food.