How to relieve a 4 year old child's stomach ache after a gastro, and is it dangerous if he has a temperature that goes up and down for 6 days?

The absence of bowel movements in the days following episodes of diarrhea and vomiting may be normal. This is because the digestive tract has somehow emptied during the vomiting/diarrhea. As for the fever, it should be of concern if it is very high (over 38.5°C) and lasts for more than 7 days. In fact, gastroenteritis with symptoms lasting longer than 7 days should be medically evaluated.

Don't hesitate if you have any other concerns.