Been nauseous and having bad diarrhea for 3 days now no fever no chills but occasionally aching and very tired. What could this be?

You might have. Viral gastroenteritis (stomach flu). Start w clear liquid like water, soda that is clear, or sports hydration drinks. Sip, sip, sip. Work up to solids w bland foods like bananas, rice, applesauce, toast, gelatin, or chicken. Avoid alcohol, nicotine, caffeine, dairy ; high fat foods. Rest. If you are having frequent, chronic symptoms - it may not be due to viral infections. If this is the case, >.