Thanks for the suggestions - I think if I'm going to change formula I may as well see how he gets on on regular formula. Will do as you suggest bonzo - start building up a ratio of comfort to normal formula. Fingers crossed I don't disrupt him too much, with weaning round the corner also!
When changing milks I've always done it gradually. Eg 7 scoops old milk to 1 of new, then 6 to 2, 5 to 3 etc over the course of a few days. Rember the comfort milk is thickened so the normal stuff will come out very fast. You might need to change to a smaller teat size.
Ds (21 weeks) has been on Aptamil comfort milk for constipation and colic since he was around 6 weeks, he is also on colief which we are currently reducing with a view to stopping completely around the time he is weaned. He is really content with the current milk he gets. The problem I have is that that particular milk is now becoming very difficult to get hold of in my area. Several stores are out of stock or discontinuing it - apparently there is a problem with the manufacturer. I think maybe it's time I switched him over to regular formula but I'm not sure how to go about it without causing ill effects. I really don't want to go back to the way he was colic wise in the early days. Should I just change one day to the normal formula or mix them together or alternate bottles? Would be grateful for any advice/experiences.