Removing a fingertip decreases the risk of acquiring an ingrown fingernail. Removing toes eliminates the risk of athletes foot or ingrown toenails. The medical benefits of cutting off fingers, toes, or foreskins do not significantly outweigh the risks and harms.
Thomas Wiswell claimed that circumcision reduced the risk of urinary tract infection by a factor of 12. No other researcher has been able to reproduce his results. Good science is reproducible, bad science is not reproducible. Wiswell's claim regarding UTI and circumcision is bad science.
ensure that you will never have penile cancer
Cutting off a girl's labia would ensure that she will never have labial cancer.
or eliminate balamitis and phimosis
There are effective non-invasive methods of treatment for balanitis and phimosis. The British Medical Association says, "to circumcise for therapeutic reasons where medical research has shown other techniques to be at least as effective and less invasive would be unethical and inappropriate."
all of this with essentially zero side effects.
The foreskin is the most sensitive part of a male's penis according to a study recently published in the British Journal of Urology.
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.
When your penis falls off to penis cancer, don’t come crying to me. That’s all I can say.
:P
No smoking, either. That just makes it worse.