Symptoms: nausea, stomachache, diarrhea, extreme sweating, faintness, lasted about 30 min. food poisoning? or could overeating have been the cause?

Maybe, but maybe not: A 30 minute bout of diarrhea, along with nausea, tummy ache, and sweating, usually means the person ate something that reacted in a way with his or her body, to make the body want to rapidly expel (poop out) everything. Sometimes this is due to food poisoning (toxins in food), rapid over-eating, certain food oils/ingredients that make bowels move, taking medications with laxative effects, etc...