When I stress out I get really bad stomach aches, it usually comes after the situation is over and I don't actually realise stressed out I've been. Like the first time I was working in the vet clinic while I was studying, I really didn't want to do it because we had to answer phones and be monitored (basically the phone had 2 things to talk on and the supervisor would stand next to you and listen to the conversation *shudder*, lucky I organised not to have to do it). I was so glad to get out of there the first day, and it was only after I walked out of the clinic to go home that I realised how much I'd been stressing, I had the most painful stomach ache. And it happened again when the cops dropped my cousin at my house in the middle of the night drunk and flipping out, after she left the pain was almost unbearable.