I had the stomach flu for 3 weeks ago and felt fine after 5 days, but now after 3 weeks i have diarrhea and chills again. should i see a doctor?

If you were fine for: A couple weeks - you could have a different gastrointestinal virus. 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.