Yellow urine after taking quadruple drugs (which may refer to quadruple therapy for H. pylori or M. tuberculosis) is suspected to be caused by drug reactions, low water intake, food, and urinary tract infections. 1. Adverse drug reactions: furazolidone or tetracycline in quadruple therapy for H. pylori can make the urine yellow, while rifampicin in quadruple therapy for M. tuberculosis can make the urine orange-red, which is a normal drug reaction, and usually returns to normal after stopping the drug. 2. Drinking too little water: drinking water during the medication is significantly reduced, making the urine concentrated, its color is yellow, and return to normal drinking water can be restored. 3. Food: carrots, pumpkins, oranges and other yellow food if too much use, will also make the urine yellow, stop eating after the urine can return to normal. 4. Urinary tract infection: in the presence of urinary tract infection, certain bacteria can interact with the urine, making the urine yellow, and the patient may also have frequent urination, urinary urgency, urinary pain and other signs of urinary tract irritation, patients in this situation should go to the hospital. In addition, the urine is yellow after taking the quadruple drug may also be related to other reasons, if necessary, to the hospital for a clear diagnosis and treatment, the specific medication as prescribed by the doctor.