Spit-up and vomiting are common at this age from normal reflux, but any medicine, including Grandem, still needs your doctor's eyes on your baby first.
Next Steps
Try smaller, more frequent feeds and keep your baby upright for 20-30 minutes after each feed to see if that helps.
Health Tips
See your pediatrician in person if vomiting continues after every feed, especially with irritability, poor weight gain, or greenish vomit.