I probably don't know every detail about it because I play with scat disabled, but there are diapers in the game, also, with pretty much every fetish in the game your character will start out obstinately opposed to willingly doing anything by choice. Traps, enemies,circumstances and "bad choices" will usually bait your character into situations where they either have to, or become more attracted to some fetishistic action.
I would guess there are ABDL hypno traps and game mechanics that decrease continence like cursed potions, clothing, etc... There are probably a couple of extra credit sequences or other "events" that force the issue. My recommendation would be intentionally not using the toilet, and messing around on different floors and generally fucking around. There's a lot in the game, and AIKA made an entire side-game diaper-quest around ABDL, scat, and pissplay fetishism on top of what's in Trapquest, so I'm guessing there's some in-depth stuff there.
