You can sue anyone for anything at any time. These lawsuits are usually messy, drawn-out affairs (we're talking YEARS) that generally end up costing way more in legal fees than it would have cost you to just fix the problems yourself.
You have to be able to prove the person who sold you the house knew about these things. Do you have proof? Thinking they "should have known" is not proof.
Secondly, what you're describing - particularly with the drain seems like something that would have shown up on a basic inspection. Did you get one? Does it make any mention of plumbing issues?
You can go talk to an attorney but you're facing an uphill battle.