In "three glass test" shreds are presents in first glass only. The most probable diagnosis is:

Three-glass test is a test to determine the location of an infection affecting the male urinary system. The bladder is emptied by passing urine into a series of 3-ounce test tubes, and the contents of the first and the last are examined; The first tube contains the washings from the anterior urethra, The second, material from the bladder, and The last, material from the posterior urethra, prostate, and seminal vesicles. If flakes or threads of pus are passed in the urine, their source is usually urethral.