In the flaccid penis, this tissue folds over on itself, covering the glans to varying degrees in each individual. As the penile shaft elongates with erection, the foreskin fold everts and is taken up along the shaft, while still retaining enough slack to maintain mobility of the penile skin sheath. With circumcision, however, the extensive loss of penile skin leaves insufficient tissue for comfortable expansion of the penis with erection. This can result in tight, painful, or bowed erections; tearing or bleeding at the scar site or on the shaft skin; or pulling of hairy skin from the scrotum and pubic area onto the shaft of the erect penis.[4-8]
Australian researchers found that circumcised men had shorter erect penises by a mean length of 8mm than intact men (p<0.05),[9] which may be due to tethering of the penis by excess skin tension.
In the case of heterosexual intercourse, once the intact penis is inserted, the vaginal walls hold the skin of the penis relatively stable, allowing the shaft of the penis to glide in and out of its own skin sheath. In contrast,
the taut, immobile skin of the erect circumcised penis lacks this natural gliding action with the motions of intercourse, creating an excess of friction directly on the vaginal walls, and potentially causing increased discomfort for both partners.[10] These dynamics also apply to anal intercourse.
The mobility of the intact penile skin also plays a facilitative role in foreplay, masturbation, and intromission (insertion of the penis), all of which are adversely impacted by circumcision.(8,11) One physician described the latter function in this way: “Penetration in the circumcised man has been compared to thrusting the foot into a sock held open at the top, while, on the other hand, in the intact counterpart it has been likened to slipping the foot into a sock that has been previously rolled up.”[12] Several researchers have noted that circumcision causes compensatory changes in masturbatory technique.[13,14] Whereas the intact male can slide the touch-sensitive foreskin back and forth over the glans to self-stimulate, the circumcised male must apply friction directly to the less sensitive glans and shaft of the penis. When masturbating,
circumcised men have been found to significantly more often require the use of artificial lubrication, and stimulation to the point of pain to achieve ejaculation.[14]