My DS had constipation after using the S26 Gold - he usually has the normal S26, but someone gave us a tin of the Gold stuff, and after a few days of being on that he became really constipated. I mentioned it to my doctor, who said that the Gold versions of formula can sometimes make babies constipated, and the normal versions are often better (he didn't really elaborate why exactly...) Anyway, we switched him back to the normal stuff and he was fine within a few days.
Maybe worth trying the normal S26? Or even a different brand? We used the coloxyl drops too, and they seem to work eventually.
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