Plumbing

We have been having problems with our kitchen sink getting plugged up--long term problems. We've had people come to unclog it, my husband has snaked it out and used chemicals in it, and nothing seems to work for very long. 
We had a guy come today, who found that the snake would only go so far, and he discovered that this pipe in the basement was the problem.  Someone sometime had put this plastic piece of pipe between the regular pipes, and you can probably see that the plastic piece is scrunched down and crumpled.  It was only allowing a narrow opening for the water to drain. Voila! Another plumber came and fixed it, and now we should have no problems with the kitchen sink draining!  Keeping my fingers crossed!