Answer: Istibrāʾ is a recommended (mustaḥabb) act performed by men after urinating in order to be confident that no urine is left in the urethra, and its not compulsory to perform. It is performed by the following way: after urinating, the anus is first purified if it has become impure; then, the middle finger of the left hand is slid three times from the anus up to the scrotum; then, the thumb is placed on the penis and the forefinger is placed under the penis, and the thumb and forefinger are pulled three times along the penis up to the point of circumcision; finally, the end of the penis is pressed three times.

Answer: If a person doubts whether he has performed istibrāʾ or not and fluid comes out and he does not know whether it is pure or not, it is impure; and in the event that he performed wuḍūʾ, his wuḍūʾ becomes void (bāṭil).
If someone who has not performed Istibrāʾ becomes confident that no urine is left in the urethra due to the passing of time since he urinated, and if he then sees some fluid and doubts whether it is pure or not, that fluid is pure and it does not invalidate wuḍūʾ either.

Answer: The fluid that sometimes comes out of the penis as a result of sexual arousal, called ‘madhī’, is pure. And the fluid that sometimes comes out after the ejaculation of semen, called ‘wadhī’, is also pure, and does not require ghusl. As for fluid that sometimes comes out after urinating and which is called ‘wadī’, if it has not come into contact with urine, it is pure. Furthermore, in the event that a person performs istibrāʾ after urinating and then fluid comes out and he doubts whether it is urine or one of these three fluids, it is pure. The passing of these liquids are pure and do not invalidate wuḍūʾ either.