For many years I have been having the same problem, severe stomach pain, around the plexus, increasing when pressed and almost immediately relieved when I make myself vomit. It keeps me awake or wakes me up if it starts at night and I also called an emergency once - they had no idea what it can be. It seems related to food, as it occurs quite soon after eating (especially when eating till completely full) and stops when the stomach content is removed but I cannot pinpoint to which foods exactly and I would say it has probably more to do with food freshness than with particular food types.
However, I had these symptoms twice in a row after eating certain spelt cookies - both times from a fresh package (but of course not freshly made) which I never buy again - few times after eating seaweed and I eat loads of seaweed, normally without any problems, few times after eating mashed potatoes even... It feels a bit like being clogged. The food stays in the stomach for 12 hrs sometimes, till I force it out (it smells bad then) but today it was different.
Today morning I ate a two-day old sandwich with seitan (I shouldn't have but I took the risk coz it looked fine), had this pain all day long till I decided to throw up but it was just enormous amounts of transparent liquid (saliva + stomach acid?) although it felt like my stomach was full of food and I ate the last meal about 3hrs before.
I have been tested for H. pylori - negative. I suspect food allergy/sensitivity, but to potatoes?
In any case food that is not absolutely fresh is a no-no for me now. I have put my guard down regarding the sandwich and I was punished immediately...
I am 31, female, had these symptoms since around the age of 16.
Answered Apr 24, 2014
Edited Apr 24, 2014