Alright I think it was just that mealworm shell then. It must have got stuck and then has only just got out.
The way you'd find a stomach ulcer would be an ultra sound done by a vet who knows what shouldnt generally be in the stomatch to spot something odd such as a stomach ulcer
Perhaps when you go to another vet about the lip you coukd ask them about checking for a stomach ulcer.
Oh and I've got no idea how people add the videos, I think they go through the taptalk app but no idea. I was trying to work it out too.