Subincision

From TheBestLinks.com

Subincision is a form of body modification. It involves the splitting of the underside of the penis, from the urethral opening (meatus) to the base. Subincision was traditionally performed by some Australian Aborigines as a rite of passage. Subincision greatly affects urination and normally requires the subincised male to sit while urinating, though the scrotum can be pulled up against the open urethra to quasi-complete the tube and allow "normal" urination, while a few subincised men carry a tube with them to aim with. Reported advantages of subincision include greater sensitivity and the effect of increased width. Disadvantages include the risk of surgery, which is often self-performed, and increased susceptibility to STDs. The ability to impregnate (specifically, getting sperm into the vagina) may also be decreased. Subincisions heal quickly—usually within 4 weeks.

Related Modifications

Splitting the urethra only to the base of the glans is called meatotomy.
Some people split the top of the penis as well, to achieve bisection. (Splitting of the top of the penis only—superincision—is quite rare.)
Splitting the glans, but not the shaft, is known as headsplitting.