A study was done in Demark (where circumcision rates are already low) and the results found that male circumcision does impact on the sexual pleasure of both men and women such as difficulty to orgasm and incomplete sexual needs fulfillment, plus more.
http://ije.oxfordjournals.org/content/early/2011/06/13/ije.dyr104.abstract

This study confirms the importance of the foreskin and shows that circumcised men experience discomfort or pain and unusual sensations (compared to intact men). As well as noting that the foreskin plays an important role during intercourse due to its sensitivity.
http://www.ncbi.nlm.nih.gov/pubmed/23374102
http://www.doctorsopposingcircumcision.org/pdf/2013-05_Bronselaer.pdf

This study confirms that circumcision does impact on the sensitivity of the glans. The glans of the circumcised penis is less sensitive to fine touch than the glans of the intact penis. Circumcised men were more sensitive along the circumcision scar were as intact men were sensitive along their glans. Therefore circumcision removes feeling from the glans due to the glans becoming an external organ when they are naturally an internal organ and over time the rubbing of clothing caused keratinization and the skin drying out.
http://www.nocirc.org/touch-test/bju_6685.pdf

This study states that younger males have more discomfort after circumcision.
http://www.jurology.com/article/S0022-5347(12)06003-X/abstract

This study notes the change in the brain caused by the level of pain an infant is in during circumcision. “[T]heir observations indicated that babies undergoing the procedure were subjected to significant and inhumane levels of pain that subsequently adversely affected their behavior’s.”
http://www.whale.to/a/mri_studies.html

This study proves that aneasthesia does not help relieve pain cause by infant circumcision. “The adrenal cortisol response to surgery was not significantly reduced by the administration of Lidocaine.”
http://cpj.sagepub.com/content/25/8/412.abstract

In this study we can see that sucrose does not help relieve pain when an infant has the routine heel lance (aka heel prick). If sucrose does not help with a heel prick how can it help with the pain management of circumcision? “Our data suggest that oral sucrose does not significantly affect activity in neonatal brain or spinal cord nociceptive circuits, and therefore might not be an effective analgesic drug.”
http://www.ncbi.nlm.nih.gov/pubmed/20817247