Drinking tap water once in a while is not a problem. The current tap water is disinfected by the water company and can reach the state of drinking, so parasites, or other disease transmission is not considered. There is hypochlorous acid in tap water, and hypochlorous acid has a disinfecting effect on toxins, so drinking tap water occasionally is not too much of a problem. If you have poor gastrointestinal function or poor digestion, or if you have recently had a cold or flu, you may have an inflammatory infection that can lead to gastroenteritis and symptoms such as diarrhea, abdominal pain or nausea and vomiting. If this occurs, it is important to pay attention to the diet, drink plenty of water, and drink boiled water whenever possible, while observing changes in body temperature and abdominal pain. If necessary, routine blood tests, as well as routine stool tests, need to be completed.