Rice poisoning is mainly caused by the growth of a large number of bacteria after the rice has been left for a long time, and some bacteria also produce toxins, and the bacteria and toxins harm the human body. Most of the reactions to rice poisoning occur in as little as half an hour or as long as 20 hours after eating leftover rice, manifesting as symptoms of acute gastroenteritis with varying degrees of abdominal pain, diarrhea, nausea, vomiting, etc. Some also have fever and headache, and patients often feel dizzy, weak, and do not want to eat, and those who vomit and have heavy diarrhea may also have varying degrees of dehydration. Other people may experience allergies such as skin flushing, headache and itchy bumps 0.5-2 hours after eating leftover rice. Light cases of rice poisoning do not require special treatment and will get better on their own; heavy cases should go to the hospital to see a doctor, and most importantly, try not to eat leftover rice.