Jack’s are likely always Bristol Type 1, and passing them is like a Nautilus gym experience that takes him at least a hour. Lots of heavy straining, with sweat collecting on his forehead. Maybe Type 2, but that’s being generous.
The only other possibility would be Type 7 mud spatter, probably when he consumes too much sugar alcohol, and ends up pissing out his asshole. I imagine the days of him passing Types 3-6 are in the distant past. Gone are the days of taking a satisfying, juicy shit that looks like he dropped a collection of stew and placenta into the toilet. It’s just dry, metamorphic rocks now.