I typically don't eat when I don't feel well. I have an irrational fear of throwing up (haven't done it in about 20 years!). If I'm being slightly rational and recognize that I must eat, I stick to very bland foods. When I was sick with a stomach thing a few months ago I ate the following:

oatmeal
water
applesauce
broth

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When you get to the end of your rope, tie a knot and swing.