Younger infants and newborns with constipation should be carefully evaluated by their Pediatrician. It is important to remember that infants that are exclusively breastfed rarely become constipated. Infrequent bowel movements do not mean constipation if your infant's stools are soft when he finally passes one. Medications used to treat infants with constipation are usually limited to colace, maltsupex, lactulose and the occasional use of a glycerin suppository.
Do contact your doctor. You can put a call into him and he will call you back.
Hope this helps.