Can a respiratory virus cause diarrhea? didn't have much appetite while sick & now that i've started eating again i get bouts of diarrhea after eating a full, heavy meal. any idea as to the cause of that?

Viral gastro-enteritis can upset the normal balance of digestive system and may precipitate disorders like lactose intolerance. Try taking Pepto-Bismol or Imodium for diarrhea. Drink enough water so that your urine is mostly colorless. If this does not resolve the issue in 2-3 days, it would prudent to see a doctor in-person. Get HPV, Flu and Covid vaccines. Wish you good health!