Q. What is circumcision? Why is it done, how common is it, and what are its effects? I've heard that it has become controversial and is on the decline. Can you give me a summary of why?

A. Circumcision is the removal of a portion of the genitals by cutting or surgery, usually from infants or adolescents. In parts of the world both girls and boys are circumcised, but in America only boys can be circumcised legally. (Recent legislation criminalized the removal of any portion of girls' genitals.)

In America, the only Western country where circumcision is still widely performed, circumcision removes the retractable outer portion of the penis, or foreskin. "Foreskin" is a misnomer; it also contains tissue beneath the skin.

Circumcision was introduced in America during the anti-sexual Victorian era; doctors hoped to prevent masturbation by reducing penile sensation.

Historically, the rationale for circumcision has shifted repeatedly. Circumcision proponents have claimed it prevents epilepsy, cancer, blindness, urinary tract infections and insanity.

Claims for circumcision as a preventive measure raise serious medical-ethical problems. Nowhere else in modern medicine do doctors routinely remove normal, healthy tissue in hopes of preventing statistically unlikely conditions that are more effectively prevented through more conservative approaches.

Circumcision has become controversial because it raises issues of infant trauma, unnecessary risks of potentially fatal antibiotic-resistant staphylococcus infections and numerous ethical concerns.

The part of the genitals removed serves a natural, protective anatomical function, and may have immune functions.

Circumcision, oddly out of place in a rationally based healthcare system, hasn't been held to the same ethical standards and scientific scrutiny expected everywhere else.

Research shows that circumcision removes the most highly-innervated portion of the penis, containing thousands of specialized nerve endings. Once removed, they never grow back. A recent study in the British Journal of Urology found that circumcision diminishes penile sensitivity by 75 percent.

Ethicists point out that circumcision deprives unconsenting minors of a fundamental human right — that deciding whether to keep one's genitals as nature intended is an individual's inalienable birthright, not a parent's or doctor's.

Much is changing: Articles in national publications, including Men's Health, have raised awareness, and parents are increasingly demanding that their sons be left intact. Statistics show U.S. circumcision rates have dropped below 32 percent in some areas. Many states now refuse Medicaid funding for circumcision, and we've begun to see lawsuits against doctors who circumcise.

Today doctors increasingly oppose routine circumcisions.

Laurie Steelsmith is a naturopathic physician and licensed acupuncturist in Honolulu, as well as author of the book "Natural Choices for Women's Health" (Random House). You can reach her and read her past columns at www.DrSteelsmith.com. This column is for information only. Consult your health provider for medical advice.