My 7 month old baby has been constipated for 6 days. hes still passing gas but no poop. im not sure what to do?

If this is the first time it happens and recently his feeding was changed then low water in the portion could be the culprit. You can give him 4 ounces of 100% juice (apple, prune or pear) and if he does not have a bowel movement in 6 - 8 hours then you can try glycerine suppository. To prevent the recurrence, increase water intake for about 20% and feed him 4 oz 100% juice daily. Good luck.