Hidden pain in the perineumPositive urine for leukocytes and occult blood may be caused by infections of the urinary system such as pyelonephritis or stone disease. 1. The causative agent of acute pyelonephritis is mostly Escherichia coli. The main symptoms include sudden chills, high fever, generalized pain as well as low back pain and bladder irritation signs. It also occurs. Frequent urination, painful urination, hematuria and other symptoms. 2. Stones can also cause the above symptoms. If the stone is located in the ureter, its typical manifestations include severe pain in the lower back and groin. In addition, the stone will also appear microscopic hematuria, leukocytosis and other symptoms. The exact cause of the disease needs to go to a regular hospital and consult a doctor to determine.