The urine is particularly smelly, then the possible causes: First, after consuming foods such as onion, garlic and durian, causing the urine to stink for a short period of time, mostly related to diet, after stopping the relevant food intake, the smelly urine can disappear. This situation is not a pathological change and does not require special treatment; second, when a purulent infection occurs in the urinary tract, or an anaerobic infection or fungal infection occurs, there will be particularly smelly urine. This is when the urine contains more pus, or there are various bacterial metabolites, etc., which can appear smelly urine. Patients are usually accompanied by urinary frequency, urinary urgency, painful urination and other symptoms of urinary tract irritation, and need to retain urine to do routine urine and urine culture tests to confirm the diagnosis; third, if there are patients with gastrointestinal or bladder surgery, there can be a vesico-rectal fistula, or vesicouterine fistula, etc., which can appear foul-smelling urine. At this time, there can also be various sediments in the urine, or fecal-like substances discharged. It is mostly associated with a bladder and intestinal fistula caused after surgery, which requires surgical repair, and is mostly seen in patients with a history of bladder or intestinal surgery.