With the trinket 'Gag Reflex', the one that gives you ipecac for the remainder of a room after using a pill, there's a bug that allows you to gain ipecac permanently for the rest of the run. I don't know exactly how I managed to produce the effect but I think I used a pill as I was transitioning between rooms and the game never removed ipecac from my items.

I know this is a minor bug but I figured it's worth it to report anything I find.