When Stewie and Brian are fighting, Stewie starts talking Spanish, and what he says translates to "I am going to kill you, ugly dog. Do you understand me, stupid? You are an imbecile. I hate you!"
Stewie says mom (mommy, ma, mum, mama) 27 times before Lois reacts.
The end credits is a reference to All in the Family (1971)
The song playing during the cutaway where Peter rips up an exam in front of the teacher is "I'm Free (Heaven Helps the Man)" sung by Kenny Loggins. It is from the film "Footloose".
Lois says prostate exams check for cancer. They check for the size of the prostate, which is most often enlarged from benign prostatic hyperplasia. Most men eventually develope an enlarged prostate, and the condition can cause serious problems with urinating. Side point: there is some debate about even testing for prostatic cancer, the argument being that some men die with it but no-one dies from it.