Caulk probably isn't the best choice.
Best choice, cut it out and replace.
As good, if you can do it, is to buy a repair coupling, cut it into to pieces, where one half is slightly larger than 180-degrees. Slobber both the pipe and the coupling up with primer and cement, and snap it over the area where the hole is (unless it went all the way through!). A repair coupling doesn't have a stop in the middle, but otherwise looks like a standard coupling used to join two pieces of pipe together.
What has been said to work, but not a great idea is to heat up a screwdriver tip and use it to melt the area and smush it to close up the joint. This will make that area thinner, and wouldn't be approved, but could work. Some also put some caulk on a ss screw, and screw it in to plug it...this would have a hook in the line to catch hair, etc., and would prevent you from ever getting a snake through there.
With four holes, maybe replacement is the best.