Under normal circumstances, the majority of urobilinogen enters the intestinal tract and is eventually excreted in the feces, only a very small amount of urobilinogen may be excreted in the urine of normal people. A negative or weakly positive urine bilirubin level is normal. A 2+ urine bilirubin level indicates abnormal bilirubin metabolism in the body. Abnormalities in bilirubin metabolism are classified as excessive bilirubin production and abnormalities in enzymes related to bilirubin metabolism that affect metabolism, which involves liver, kidney and gastrointestinal tract pathologies. On the one hand, it may be caused by increased production of urobilinogen, mainly seen in excessive destruction of red blood cells, such as in hemolytic diseases. On the other hand, it can also be caused by a weakened uptake or metabolism by the liver. Clinically, it is mainly seen in hepatocellular damage caused by various reasons, such as viral hepatitis, cirrhosis, autoimmune liver disease, alcoholic liver disease, etc. Therefore, the presence of urobilinogen 2+ requires active investigation of the cause. However, urobilinogen 2+ alone is not enough to determine the specific cause of this abnormal condition, and further analysis is needed in conjunction with the patient’s medical history, symptoms, signs, routine blood tests, liver function, liver imaging and other relevant tests.