D.S.
Hey Christine,
Does the formula have extra iron because that can definitely constipate babies. Check with your doctor but when my son was little we used to give them a little sugar water and that used to help him to go to the bathroom. He also was very constipated as a baby. Using the thermometer, or the suppositories will not hurt as long as you use it gently but it is only a temporary solution. I know with breastfed babies you are not supposed to give water, but maybe with the formula the doctor will allow a little. Once you put him on solids you can introduce prunes and diluted prune juice. Good luck!!