Reflux in babies is a common occurrence, especially around 4 months of age. To help reduce reflux, you can try giving your baby shorter feeding sessions with breaks, keeping them upright after feeding, offering thickened formula if they are formula-fed, avoiding tight clothing or diapers, introducing solid foods if they are old enough, or trying hypoallergenic formula if needed. If your baby is not gaining weight, vomiting forcefully, experiencing yellow or green vomit, or showing other concerning symptoms, it is important to consult with a pediatrician.