do take time of 3-7 days for improvement and control of symptoms.
It is vital during this time that he continues to drink more and eat so that the dehydration
and any other ill effects due to loose stools are prevented. He also need to take adequate rest. Hand washing is particularly important before eating food/after going to comfort room etc.
Sleepiness/Drowsiness/Headache can be due to disturbances in his salt level in the body due to illness. It is advisable to get a medical opinion
as soon as practically possible.
Hope you find my advice helpful
Dr Tejas Shah