If you fail your Fortitude save vs. an otyugh's stench, you're sickened 1. If you critically fail, you're also slowed 1 "for the same duration". But I can't find anything that states what the duration is. Does sickened have a standard duration, or does it always persist until you get rid of it by retching? And if so, does retching also remove the slowed condition?
Related question: if you successfully remove the sickened condition by retching, do you become immune to the stench for an hour as if you'd succeeded at the initial save?