Baby vomitting after breastfeeding and restless when he is awake plus he did not get a stool for 3 days?

Constipation: The age of the baby matters, but other reasons for vomiting needs to be evaluated and intestinal obstruction ruled out. Please go see a Pediatric doctor in an ER or urgent care setting where an Xray is available if needed. Simple Stool softener agents and/or suppository should relieve the blocked stool issue, but go see a doc to be sure