How long does it take for someone to get over the intestinal flu. I have been on liquids to calm my sensitive stomach down since Tuesday April 4 and have sinusitis also. I finally ate today since it is the weekend. I ate some crackers and a half a banana. I work on the phones and could not afford to have diarrhea. So before this I was trying just to keep my stomach calmed down. I have been on water and gatorade. And when I had previousIy started drinking chicken bouillon to get something more on my stomach. I got diariah. So after two days of two cups a day I stopped and went back to water and gatorade. Just still feel tire and drained.