An unfortunate side effect of formula, poor bubba. Formulas all have added minerals/iron etc, which for some bubba's are to much, and just like us the extra iron can cause constipation. If it is really severe you can use coloxyl drops. You can try switching formulas to a softer one like karicare or even drop back to the regular s26, it will still provide adequate nutrition. My niece couldnt handle s26 gold but karicare was fine, but some other babies are different again.