Ascariasis is the parasitization of the human small intestine by roundworms, and children become infected by ingesting the eggs of infective stage worms. Mild cases have no obvious symptoms, but ectopic parasitism can often lead to biliary ascariasis, intestinal obstruction and other serious complications. (1) Lungs: fever, cough, asthma, bloody sputum, ascaris lumbricoides visible in sputum, eosinophilia, chest X-ray shows a transient shadow. (2) Liver: there may be transient hepatitis, right upper abdominal pain, hepatomegaly, and abnormal liver function. (3) Heterotopic manifestations: pleurisy, epilepsy, retinitis, etc. (4) Systemic allergic symptoms: urticaria, itchy skin facial edema, acute conjunctivitis, asthma and so on. 2, adult worms cause disease (intestinal ascariasis): mild cases can be asymptomatic, or repeated episodes of pain around the umbilicus, like to press, no pressure pain and abdominal muscle tension, sometimes nausea, vomiting, mild diarrhea or constipation malnutrition. There may be a history of deworming. Occasionally night terrors, teeth grinding, depression or irritability and other neurological symptoms. 3.Complications: Ascaris lumbricoides has the habit of wandering drilling holes, when too many roundworms or pediatric hyperthermia dyspepsia, a large number of spicy food, improper deworming and other conditions can make the worm commotion. (1) Biliary ascariasis: it is the most common serious complication. It manifests as paroxysmal commotion. Severe colic in the right upper abdomen, after the colic remains micro-pain. Some patients may also develop cholangitis, cholecystitis, pancreatitis or liver abscess. (2) Ascaris lumbricoides intestinal obstruction: it is common in young children. It is characterized by sudden paroxysmal severe pain around the umbilicus or lower abdomen, visible intestinal pattern and peristaltic wave, and ascaris lumbricoides mass or spastic intestinal tube can be felt in the abdomen, and the shape and location of the mass often change. (3) Ascaris intestinal perforation and peritonitis: caused by perforation of roundworms from small intestine or appendix into the abdominal cavity. The manifestation is sudden severe abdominal colic, with obvious peritoneal irritation symptoms, abdominal X-ray examination can see free gas under the diaphragm. In addition, comatose patients, roundworm upward, drilling into the trachea can cause asphyxiation; roundworm fragments and eggs are related to the formation of gallstones.