Kitchen sink is draining very slow on both sides. When water is draining it will go to the other side and drain very slowly. It happens to both sides. We have used professional gel and have replaced several sections of PVC pipe under the sink and in the basement. The problem still persists. Any suggestions?

You have blockage in the drain line and you need to the "J" bend from the trap and send a snake up into the wall, You will hit a bend about 8 inches in but once around that you only have to put out 5 feet more, good luck

John