Roundworms in the human stomach are harmful to both adults and children.

Ascariasis is a parasitic disease caused by roundworms parasitizing the human small intestine or other organs. It is widespread and has a high incidence rate in children.

After swallowing the infectious eggs, the larvae hatch in the small intestine. When the blood flows through the lungs, their metabolites and the death of the larvae can produce an inflammatory reaction. Damage to the capillaries by the larvae can lead to bleeding and cell infiltration, leading to serious infection. The lung lesions of patients can fuse into sheets, the bronchial mucosa is infiltrated with eosinophils, and inflammatory exudates and secretions increase, leading to bronchospasm and asthma.

Adult worms parasitize in the jejunum and upper ileum. The worms can secrete digestive substances and attach to the intestinal mucosa, causing upper cell shedding or mild inflammation. Large numbers of adult worms can tangle into clumps and cause unsafe intestinal obstruction. Roundworm boring can cause ascariasis in the bile duct, pancreatic duct, appendix, etc. Biliary ascariasis can be complicated by acute pancreatitis or chronic pancreatitis, and ascaris eggs and fragments may be related to the formation of gallstones.