Constipation is actually very common when starting solids. Your baby’s gut isn’t used to processing very much, so it takes some time to adjust. The good news is that most babies will get used to the process and the constipation will improve.
In the meantime, try offering pea, prune or pear purée as as these are known to help relieve constipation. You can also use baby oatmeal instead of the more traditional rice cereal for more fiber. Be sure your child is still getting a good amount of formula/breast milk to provide adequate fluids.
If your little darling is still constipated, you can try a small amount of pear juice. Start with 1/2 ounce of pear juice mixed with 1/2 ounce of water twice daily, increasing up to 1-2 ounces per day if needed. Keep in mind that more than 4 ounces of juice per day is not recommended and should not replace any food, formula or breast milk intake throughout the day.
A warm bath or gentle tummy massage can also do the trick!
Let me know if you need more help. If your baby is really backed up or producing small, hard stools, call your pediatrician to discuss.