The diarrhea talk a few pages back reminded me of a bad experience a few years back.
I got hit with a gastro bug - anything that went in, went out again within ten minutes, massive amounts of abdominal pain whenever I ate anything - in short, not fun. Doctor says it's going around, will be gone in a week or so, just take plenty of fluids etc etc.
I arm myself with electrolyte drinks and plain water crackers and wait for it to end. Luckily it's study week so I can just stay at home with my textbooks and family can duck out for grocery runs in emergencies.
Slooooowly getting better, still doing the eat-agony-toilet cycle. Just come out of the bathroom after a full scale 'evacuation', when I realise I need to pass gas.
Eh, it will be fine. It's just a fart. There is absolutely, positively, nothing left, right? Wrong.
Cue me frantically running back to the bathroom, wailing for my grandmother to kindly fetch me a new pair of undies please, and staying on the toilet for another ten minutes (vowing solemnly to never trust a fart again).
(Luckily for me, it cleared up in time for me to sit my exams).