My friend had the stomach flu 3 days ago and was planning on going on a trip should i go?

Health precautions: If your friend has COMPLETELY recovered --no more diarrhea-- then I would feel much better about traveling together. It's always good to practice 'good hygiene' such as washing hands before meals, NOT touching your face at any time, not sharing drinks/utensils, etc. Stomach flu is highly contagious, but if it's already been 3 days I feel a lot better about you traveling together.