The foreskin has several functions and accounts for a lot of the sensitivity of the penis.
The normal glans is an internal structure, only exposed briefly during urination, washing, and sexual arousal. Its surface is moist and is not keratinised. However, circumcision converts the glans into an external organ. Immediately after the operation, it retains its exquisite sensitivity, and contact with clothing causes considerable discomfort, but it soon becomes desensitised, probably as a result of the laying down of a layer of keratin on the epithelium. A few circumcised men report persistent discomfort from contact with clothing throughout their lives. The epithelium takes on the character of skin instead of a mucous membrane. Not only is the appearance of the glans altered, but also there is a dramatic loss of sensitivity.
A keratinised circumcised penis and an uncircumcised penis.
A comparison of the fine-touch sensitivity of an uncircumcised penis and a circumcised one.
No data is collected on the complications and risks of circumcision in America as there is no legal obligation to do so. Infections, haemorrhages, meatal strictures, (partial) amputations of the penis, deaths and many other complications occur. Circumcision causes thousands of deaths annually, all over the world. Babies die in the USA every year.
http://cirp.org/library/death/
Pictures of complications in adults
Pictures of complications in infants
Pictures of complications in tribal men
Many cut men suffer from meatal stenosis
The prepuce
C. J. Cold, J. R. Taylor
This is not a direct quote, some of the findings have been paraphrased briefly.
The glans penis mostly has free nerve endings, which are primarily protopathic. The foreskin, the frenulum, and the ridged band of the foreskin have many nerve endings. They contain specialised nerve endings, like Meissner's corpuscles/tactile corpuscles, which are used for fine-touch sensation, Pacinian corpuscles, which sense vibration and pressure, and Merkel cells, which are essential for light touch sensation.
The prepuce: specialized mucosa of the penis and its loss to circumcision
J.R. Taylor, A.P. Lockwood, A.J. Taylor
"The amount of tissue loss estimated in the present study is more than most parents envisage from pre‐operative counselling. Circumcision also ablates junctional mucosa that appears to be an important component of the overall sensory mechanism of the human penis."
Fine‐touch pressure thresholds in the adult penis
Morris L. Sorrells, James L. Snyder, Mark D. Reiss, Christopher Eden, Marilyn F. Milos, Norma Wilcox, Robert S. Van Howe
"The glans of the circumcised penis is less sensitive to fine touch than the glans of the uncircumcised penis. The transitional region from the external to the internal prepuce is the most sensitive region of the uncircumcised penis and more sensitive than the most sensitive region of the circumcised penis. Circumcision ablates the most sensitive parts of the penis."
Male circumcision decreases penile sensitivity as measured in a large cohort
Guy A. Bronselaer, Justine M. Schober, Heino F.L. Meyer‐Bahlburg, Guy T'Sjoen, Robert Vlietinck, Piet B. Hoebeke
"This study confirms the importance of the foreskin for penile sensitivity, overall sexual satisfaction, and penile functioning. Furthermore, this study shows that a higher percentage of circumcised men experience discomfort or pain and unusual sensations as compared with the uncircumcised population. Before circumcision without medical indication, adult men, and parents considering circumcision of their sons, should be informed of the importance of the foreskin in male sexuality."
The effect of male circumcision on sexuality
DaiSik Kim, Myung‐Geol Pang
"There was a decrease in masturbatory pleasure and sexual enjoyment after circumcision, indicating that adult circumcision adversely affects sexual function in many men, possibly because of complications of the surgery and a loss of nerve endings."
Male circumcision and sexual function in men and women: a survey-based, cross-sectional study in Denmark
Morten Frisch, Morten Lindholm, Morten Grønbæk
"Circumcision was associated with frequent orgasm difficulties in Danish men and with a range of frequent sexual difficulties in women, notably orgasm difficulties, dyspareunia and a sense of incomplete sexual needs fulfilment. Thorough examination of these matters in areas where male circumcision is more common is warranted."
Cultural background, non-therapeutic circumcision and the risk of meatal stenosis and other urethral stricture disease: Two nationwide register-based cohort studies in Denmark 1977–2013
Morten Frisch, Jacob Simonsen
"Our study provides population-based epidemiological evidence that circumcision removes the natural protection against meatal stenosis and, possibly, other USDs as well."
False beliefs predict increased circumcision satisfaction, as seen in a sample of American men
Brian D. Earp, Lauren M. Sardi, William A. Jellison
"Critics of non-therapeutic male and female childhood genital cutting claim that such cutting is harmful. It is therefore puzzling that ‘circumcised’ women and men do not typically regard themselves as having been harmed by the cutting, notwithstanding the loss of sensitive, prima facie valuable tissue. For female genital cutting (FGC), a commonly proposed solution to this puzzle is that women who had part(s) of their vulvae removed before sexual debut ‘do not know what they are missing’ and may ‘justify’ their genitally-altered state by adopting false beliefs about the benefits of FGC, while simultaneously stigmatising unmodified genitalia as unattractive or unclean. Might a similar phenomenon apply to neonatally circumcised men? In this survey of 999 US American men, greater endorsement of false beliefs concerning circumcision and penile anatomy predicted greater satisfaction with being circumcised, while among genitally intact men, the opposite trend occurred: greater endorsement of false beliefs predicted less satisfaction with being genitally intact. These findings provide tentative support for the hypothesis that the lack-of-harm reported by many circumcised men, like the lack-of-harm reported by their female counterparts in societies that practice FGC, may be related to holding inaccurate beliefs concerning unaltered genitalia and the consequences of childhood genital modification."
