If a patient eats a small amount of undercooked yam and has no past history of gastrointestinal disease, it is usually observed for 24 hours, and if there are no typical symptoms, it is unlikely to lead to poisoning. However, if the patient has an obvious history of gastrointestinal system diseases, such as gastroduodenal ulcer, upper gastrointestinal bleeding, then if the patient takes a large amount of undercooked yam, it is easy to lead to the emergence of poisoning. At this time, the patient will have varying degrees of nausea, vomiting, acid reflux, heartburn, especially colic around the navel, and the patient will have diarrhea, scanty stools, mucous pus and blood stools, which must be seen immediately at the hospital. If cyanosis also occurs, it proves that typical symptoms of poisoning are present and systematic detoxification treatment must be carried out.