When your baby boy is circumcised, you will have to care for his penis as it heals. It is important to clean the penis each time you change a diaper and apply petroleum jelly to the wound. You can apply jelly directly to the penis or apply it to the diaper in the area where it touches. Skin usually heals within 7 to 10 days. You may notice that the penis tip is red and there is some yellow fluid present. This usually indicates that the penis is healing.