I'm amused by the notion that Monsters uses anywhere near the potty humor to get its effect. It's night and day. First, We went to see Shrek in the theater four times (that's right, four) and we, of course, own and watch the DVD. I think it's hilarious.
But there's no comparison of how Shrek makes use of "9 year old boy" humor v. that used by Monsters.
Voice, I'm troubled by 2 of your 4 Monsters examples. First, are you actually saying the notion that two males living together and just might be gay is an example of "potty humor"? Second, Boo had to go to the bathroom. Sully couldn't take her in the ladies' room. He had no choice. Each time I go to WDW with my 4 year old, I often have to take her in the men's room. Is that lurid behavior? Or twisted further, an example of "potty humor" somehow?
Here's another Shrek moment, and you have to listen very closely. When the dragon is first trying to charm Donkey and Donkey tries to fend off her advances listen as the focus shifts to Shrek moving in on the chain.
Donkey says, "that's my personal space" then in perfect Eddie Murphy fashion he injects "HEY, what are you going to do with that?" That's one of the funniest moments in the movie, and definitely not rated G.
How about the Robin Hood sequence with Robin's rhyming song. Forgive me for not knowing the exact words, but robin ends a sentence with a word that rhymes with "head" and the next line is: "she likes to give..." at that moment the merry men interrupt.
"Just becasue she lives with seven men doesn't mean she's easy"
"Dead broad off the table"
"I'm the talkinest damn thing you've ever seen"
The level of graphic description that Shrek used to describe what he would do to people.
The earwax candle
The catepillar inards toothpaste
The frog and snake balloons
Fiona's well-timed belch
There's plenty more examples of "grossness" and "potty humor" that Shrek used to make the film work.
And so far all that's been offered up (legitimately) for monsters is toilet paper on the foot and Mike landing on his Jewels.
None of this matters to me, it's just an absurd comparison.