Grayson went thru the ringer. They tried tons of formula and different calories. When she finally came home from the hospital she was on pregestimil 24 cal plus we added fruit pectin to help with digestion. Then she went up to 27 calories. Now she is almost 12 months and does pediasure and now trialing Kid Boost 1.5 cal/ml. She takes 4 capsules of creon 5 with meals and 1-2 with snacks. Good Luck. Graycie is battling a cough again. We upped treatments too. This first year has been very tough for our entire family.