When the number of roundworms in the intestine is small, patients generally have no special discomfort. When roundworms gradually increase, patients will have symptoms such as emaciation, malnutrition, gastrointestinal discomfort, and pain around the umbilicus and abdomen. When there are more roundworms and they gather into clusters, patients will have abdominal cramps and symptoms related to intestinal obstruction, such as no exhaustion and no defecation. When roundworms enter into the appendix, patients will show pain in the right lower abdomen, and the examination will be pressure pain in the right lower abdomen, similar to the symptoms of appendicitis. When the roundworm enters the biliary tract by the duodenal papilla, it will show symptoms of biliary obstruction such as biliary colic, yellow staining of skin and sclera, elevated body temperature, and even chills and high fever. When the roundworm enters the pancreatic duct, it will show symptoms of pancreatitis such as pain in the left upper abdomen and elevated pancreatic amylase. Moreover, patients will have itching symptoms in the anus at night and can also see adult worms crawling out from the anus.