If your 6-week-old baby is constipated and has not had a bowel movement in 3 days, there are some steps you can take to help relieve the discomfort. Try increasing the frequency of feedings if your baby is breastfed, and offer more liquids if they have started eating solid foods. Foods rich in fiber, such as prunes, oatmeal, and sweet potatoes, can also help. Gentle massages on the baby's belly and encouraging leg cycling while lying on their back may also provide relief. If these methods do not work within a couple of days, you can consider using a gentle laxative recommended by a healthcare professional. Remember to always consult with a doctor before using any medication for a baby's constipation.