The main source of urobilinogen in the human body is the metabolism of hemoglobin by the liver after the destruction of the patient’s red blood cells, resulting in the formation of bilirubin. After the bilirubin changes from indirect bilirubin to direct bilirubin, it enters the intestine with the bile excretion of the patient, and then goes through the bile-intestinal circulation in the intestine and is then utilized in the liver, which accounts for about 80% of the urobilinogen. In the urine of a normal person, the urinary bilirubinogen is generally weakly positive and is considered normal; if the patient has a negative urinary bilirubinogen, the patient is considered to have the possibility of biliary obstruction. Further ultrasound of the upper abdomen and liver function tests are needed to determine whether the patient has biliary obstruction and the cause of the obstruction. In addition, in some patients, if urobilinogen is elevated, it may be due to the possibility of hemolytic disease and hepatocellular jaundice.