Heart to Stomach - Act 5 Side Quest
Start Location: Heuneberg
Quest Location: Hercynian Forest
Objective: Speak with Caomine in Hercynian Forest then return to Orsos
Heart To Stomach is a Side Quest which you start in the town of Heuneberg, the second large town you come across in Act 5 and the second town with a Portal. You'll find Orsos, the quest giver, near the Heuneburg entrance that you came in when you first arrived in town. While on the path leading into the city make a quick left to find Orsos.
For this quest you will need to speak with Orsos' wife in Hercynian Forest. I find that the easiest way to remember where his wife can be found is to remember that immediately after you come down from the mountain where you speak with Brigarigos you'll want to cross the river off to the east. Brigarigos is part of The Warrior Princess quest and can't be skipped so he is a helpful landmark.
Once you've spoken with his wife the quest will automatically complete. You can return to Orsos and speak with him too but he'll just talk about how great his wife is (if only he knew).