I'm having trouble with DS2 sleeping through the night

I though if i did it gently he would just grow out of it but not so sure now. He goes into his cot with a bottle of milk sometimes he will want another sometimes he will fall asleep on the first. He was only waking once through the night but now he's waking more often and wanting milk after mik all night.. it's driving me crazy!!

Don't know if i should continue on the gentle way or just refuse him to have milk throught the night and only give him water from then on.

Any pointers or thoughts would be great.