After hydrocele surgery, decreased excretion of pus gathering may be caused by postoperative complications, such as pyelonephritis, sepsis, renal failure and other diseases. 1. Pyelonephritis: it belongs to upper urinary tract infection, which can be secondary to hydronephrosis surgery, and it can be seen as chills, fever, headache, frequent urination, urinary discomfort, lumbar pain, etc., which will cause the decrease of pus excretion function. 2. Pus kidney: it is extensive purulent lesion caused by serious infection of kidney, patients may have high fever, chills, purulent urine, lumbar pain and other discomforts, which will cause the decrease of pus excretion function. 3. Renal failure: it is a pathological state of partial or total loss of renal function, often accompanied by dry mouth, mild headache in upright position, decreased urine output and other symptoms, which will cause decreased excretory function of pus poly. After hydrocele surgery, pus poly excretory function may also have other causes, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy.