No, we had no constipation here while DD was on Losec (from about 2-6 months old). Infants friend is good for constipation and my understanding is its all natural.

It seems he has had a bit of a run around with the different constipation methods and with the gaviscon, coloxyl, prune juice and the losec, its alot for a little babies tummy to handle. IYKWIM.

Could it be something your eating thats upsetting his tummy?