http://www.mothersagainstcirc.org/fleiss.html
* Circumcision denudes: Depending on the amount of skin cut off, circumcision robs a male of as much as 80 percent or more of his penile skin. Depending on the foreskin's length, cutting it off makes the penis as much as 25 percent or more shorter. Careful anatomical investigations have shown that circumcision cuts off more than 3 feet of veins, arteries, and capillaries, 240 feet of nerves, and more than 20,000 nerve endings.31 The foreskin's muscles, glands, mucous membrane, and epithelial tissue are destroyed, as well.
* Circumcision desensitizes: Circumcision desensitizes the penis radically. Foreskin amputation means severing the rich nerve network and all the nerve receptors in the foreskin itself. Circumcision almost always damages or destroys the frenulum. The loss of the protective foreskin desensitizes the glans. Because the membrane covering the permanently externalized glans is now subjected to constant abrasion and irritation, it keratinizes, becoming dry and tough. The nerve endings in the glans, which in the intact penis are just beneath the surface of the mucous membrane, are now buried by successive layers of keratinization. The denuded glans takes on a dull, grayish, sclerotic appearance.
* Circumcision disables: The amputation of so much penile skin permanently immobilizes whatever skin remains, preventing it from gliding freely over the shaft and glans. This loss of mobility destroys the mechanism by which the glans is normally stimulated. When the circumcised penis becomes erect, the immobilized remaining skin is stretched, sometimes so tightly that not enough skin is left to cover the erect shaft. Hair-bearing skin from the groin and scrotum is often pulled onto the shaft, where hair is not normally found. The surgically externalized mucous membrane of the glans has no sebaceous glands. Without the protection and emollients of the foreskin, it dries out, making it susceptible to cracking and bleeding.
* Circumcision disfigures: Circumcision alters the appearance of the penis drastically. It permanently externalizes the glans, normally an internal organ. Circumcision leaves a large circumferential surgical scar on the penile shaft. Because circumcision usually necessitates tearing the foreskin from the glans, pieces of the glans may be torn off, too, leaving it pitted and scarred. Shreds of foreskin may adhere to the raw glans, forming tags and bridges of dangling, displaced skin.