Oh guys I know how that feels. Once I'd had muesli and that's horrible to throw up through rumination because of how pointy and sharp all the bits are. :S
But anyways, I walked out to the marshes near where I live and as I was walking back it all started coming up in huge amounts, no-one was around so I just spat them out on the grass etc. Then I walked through a tunnel underneath the road, and suddenly I throw up again. This was some months ago but I'm tempted to go back to see if the stain is still there...lol.