In another toilet-centric experiment for Barry Test, our guinea pig Sim, we gave Barry a phone and made him order a pizza. Once it had arrived, we placed the pizza in an empty room next to a toilet, and then built a wall around Barry to lock him in place. Hours later, when Barry urgently needed to empty his bowels, but at the same time really needed something to eat, we freed him to see whether he went for pizza or potty.
Even though the pizza was cold and about to go off, Barry made a beeline for the fast food. Once he'd eaten a slice, he went to the toilet. It's almost poetic.
Although Barry went for the pizza, his immediate desires kept switching between toilet and food right up until he was released. To be honest, it could've gone either way. The needs of Sims to eat and defecate are alternating and equally important.