As I lay awake wondering if I should take some ibuprofen at 3am this morning (menstrual cramps) I was trying to work out whether my stomach was ‘too empty’ or not. I had a big roast dinner around 6pm - so that was 7hrs ago - but how fast is digestion? How much do you need to eat to protect your stomach from Ibu anyway? If I eat a slice of toast can I have some straight away or do I need to wait for a bit? Am I over thinking? Is there a rule of thumb?