Ben: I've been waiting on this moment ever since I first laid eyes on you.
Malcolm Turner: Ben, whatever you started in that bed, trust me, you're going to finish alone.
Nolan: Now lets say you walking down the street, strutting yo stuff, and someby yells out and screams "Hey baby! Why don't you back that thing up and show me whatcha got and whatcha gon do?"
Big Momma: I'd say imma size 10, and I'm about to cram it up his boney ass.
Big Momma: Somebody better tell me something, cause this show is some freaky shit.
Sherry: Oh, it's so good to see you, Big Momma. I thought you may forgotten all about me.
Malcolm Turner: Shut your mouth, child. Oh, Big Momma could never forget that ass.
Sherry: What?
Malcolm Turner: ...ma. Asthma. Do you remember you had asthma?
John: Is that morphine in there? God, beats the hell out of aspirin.
Answer: The "draining noises" are Big Momma taking a dump. Big Momma didn't flush either so I'm assuming he took a look at her stools and what he saw made him feel sick.