If there is a part of the incision that is open, dont put anything on it that will keep it moist. You want the area to dry up and scab over. You are post op day number 4 and it should be dry by now. Clean the incision with some warm water, making sure nothing is coming out. Take a band aid (use it as a steri strip) take the sticky part of the band aid and place it on one side of the incision pulling the skin together, closing the incision and put the other sticky area on the opposite side . I would try not to get the area wet for at least a day, probably 2. Then take the band aid off to see if the incision closed. If the incision is oozing thick green or white discharge or doesnt close, you should call your doctor