Rice water is another fast, effective remedy for diarrhea. Boil 1 cup of rice and 2 cups of water for about 10 minutes, or until the water becomes cloudy. Strain the rice and preserve the water for consumption. Rice water not only provides your body with fluid to prevent dehydration, it can also reduce the duration of diarrhea. Rice water has a binding effect in the digestive tract, resulting in firmer, bulkier stools.