Changing from comfort to normal formula

[gruffalobore]

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.

Shameless bump!

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.

Can you change to a different comfort milk?

They are pretty much all the same although flavour might be a bit different, just advertising leads you to believe otherwise.

When we changed from nutriprem to normal formula we did it the same as Bonzo.

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!

Thanks Pennie for bumping for responses! What's your situation? Has Aptamil comfort run out where you are too?
I've bought the last of the supplies in my area! (North East Essex)