Venereal disease?

I once had a colleague who frequented bars and sleazy joints. When he had contracted the so called STD - sexually transmitted disease - he called me for help. The symptom is difficulty in urinating and later there would be pus, that yellow liquid and sometimes there is also blood.

I brought him to the doctor who took a slide for the sample. Peering into the microscope, the doctor had identified the microbe. Fortunately, after 3 days of taking the medication, the symptoms vanished.