Fecal occult blood test Once a year Laboratory examination of stool sample
Flexible sigmoidoscopy Every five years Examination of lower portion of the colon (sigmoid colon) with a lighted scope done in the doctor’s office Double contrast barium enema Every five years X-ray procedure of the lower bowel Colonoscopy Every 10 years Examination of the entire bowel with
a lighted scope, done under general sedation in a gastroenterology facility
*For those at average risk; people with additional risk factors should begin routine screening procedures at younger ages and repeat them more frequently, according to physician recommendation.
contraception 97
physically difficult. Following diagnosis and treat- ment for colorectal cancer, health experts recom- mend colonoscopy at one-year, three-year, and five-year intervals. Nutritious eating habits, regular physical exercise, no smoking, MEDITATIONor other stress relief methods, loving support from family and friends, and a positive outlook shape the most conducive environment for healing.
See also ALCOHOL AND HEALTH; GASTROINTESTINAL
SYSTEM; NUTRITION AND DIET.
complementary medicine See INTEGRATIVE
MEDICINE.
computed tomography (CT) scan A noninva- sive imaging procedure in which multiple X-rays are taken in longitudinal (cross-sectional) slices that a computer then assembles into two-dimen- sional images. A CT scan can present visual images of nearly any organ or tissue within the body and can be used for diagnosis or to guide invasive or surgical procedures. Sometimes the radiologist administers a contrast solution to improve the vis- ibility of certain tissues and structures. A CT scan can focus on a specific organ or area of the body, or cover the entire body. The first use of a CT scan was to examine the brain following stroke to assess the extent of damage. Currently, doctors use a CT scan for a wide range of diagnostic pur- poses. Because the X-ray exposure is significantly higher than with conventional X-rays, a CT scan should be done only when its findings have ther- apeutic significance.
See also ELECTRON BEAM COMPUTED TOMOGRAPHY
SCAN; MAGNETIC RESONANCE IMAGING.
conception The union of a man’s sperm and a woman’s ovum (egg) and its implantation in the uterus as the first stage of pregnancy. Conception can take place when a woman has sexual inter- course around the time she is ovulating (the point in the menstrual cycle when the ovary releases an egg), roughly between the 12th and 17th days of her monthly cycle. When released from the ovary, the egg travels up the fallopian tube. After ejacula- tion, sperm enter the woman’s uterus through the cervix and then travel down the fallopian tube. Fertilization typically takes place in the fallopian
tube; the cluster of cells that forms (called a blasto- cyte) drops into the uterus and implants in the uter- ine lining. Conception also can take place through artificial insemination and in vitro fertilization.
See also CONTRACEPTION; FERTILITY. condom See CONTRACEPTION.
congestive heart failure See HEART DISEASE.
conjunctivitis An inflammation of the conjunc- tiva, the tissues of the inner eyelids. A highly con- tagious bacterial infection, commonly called “pink eye,” causes most conjunctivitis. Bacterial conjunc- tivitis requires a doctor’s examination and treat- ment with antibiotic ophthalmic drops or ointment. Symptoms include redness, swelling, itching, and crusting of the eyelids. It is easily spread from one eye to the other by rubbing the eyes in response to the irritation. When treated with antibiotics, the symptoms of bacterial conjunctivitis generally go away within a day or two, though it is important to continue using the antibiotic for as long as pre- scribed. Many antibiotic preparations for treating bacterial conjunctivitis include a steroid anti- inflammatory drug such as prednisolone to relieve the swelling and itching. People who have allergies to oral forms of the antibiotics in an ophthalmic preparation may have hypersensitivity reactions to the ophthalmic preparation as well.
A localized contact reaction also can cause con- junctivitis. This can happen when rubbing the eye- lids with a contaminant on the fingers or when a contaminant blows into the eye. Contaminants can be any substances that are foreign to the body, from dust and pollen to chemicals. Rinsing the eye with water or a saline solution at the time of the contact can minimize the reaction. After the reaction devel- ops, a doctor might prescribe anti-inflammatory eye drops to soothe the irritated tissues.
See also VISION HEALTH.
constipation See GASTROINTESTINAL SYSTEM.
contraception A method for preventing preg- nancy. Abstinence (refraining from sexual inter- course) and surgical sterility (VASECTOMYin a man
ways to prevent pregnancy. Other methods have varying success rates. In an ideal context, men and women share equal responsibility for contracep- tion and discuss the ways they will do so. However, a man sometimes presumes the woman is taking measures to prevent pregnancy or, in the heat of the moment, does not consider the need for con- traception. Conversely, sometimes the woman pre- sumes contraception is the man’s responsibility, feels it is a “safe” time of the month during which she cannot become pregnant, or, in the heat of the moment, does not consider the need for contra- ception. Clear and open communication about contraception is essential in any sexual relation- ship. Couples who do not wish to become pregnant should practice a reliable method of contraception each time they engage in sexual activity, even if intercourse is not intended.
A man becomes fertile (capable of impregnating a woman) when he begins to develop secondary sexual characteristics such as pubic hair, and remains fertile all his life. A woman is fertile a few days each month from the time she begins men- struating until she is past menopause (a year with- out menstrual periods), a period that spans nearly five decades for most women. A woman can become pregnant the first time she has sexual intercourse, from vaginal contact with semen on her partner’s or her fingers, when she is breast- feeding, and during points of her monthly cycle that she does not consider herself fertile. The time sperm can survive in the woman’s reproductive tract is widely variable. In general, couples should consider the woman capable of conceiving during any act of sexual intercourse unless the woman is clearly beyond menopause or has had a hysterec- tomy (surgical removal of the uterus).
Shared Contraceptive Methods
There are three methods of contraception in which a man and woman share participation. They require partners to communicate closely and to trust in the accuracy of their communication. None of these methods provide protection against sexu- ally transmitted diseases (STDs). Their success rate is variable but in general not very high, in part because they interfere with the enjoyment of sex- ual activity, so couples are less inclined to follow
them, and in part because the normal variations in body cycles make these methods inherently less accurate.
Abstinence Refraining from sexual intercourse prevents pregnancy, though not surprisingly is not a popular option among sexually active couples. Though couples can have sexually satisfying encounters by pleasuring each other in ways other than through intercourse, the risk is high that a man’s semen can come into contact with the woman’s vagina.
Rhythm Often a contraceptive choice because of religious beliefs, the rhythm method, also called periodic abstinence, relies on refraining from inter- course during the week surrounding the woman’s ovulation. The rhythm method is most reliable when the woman’s cycle is precise and predictable, and when the couple strictly adhere to the timing. Ovulation test kits, available over-the-counter in pharmacies and drugstores, can help to more accu- rately pinpoint ovulation.
Withdrawal With this method the man with- draws his penis from the woman’s vagina before ejaculating. Known medically as coitus interrup- tus, this method tends to be dissatisfying for both partners. It requires the man to be able to sense how close he is to ejaculation. Because there often are sperm in the fluid that precedes EJACULATION, called pre-ejaculate, the risk of pregnancy with this method is high.
Contraceptive Methods for Men
There are two methods of contraception for men, condoms and vasectomy. Though researchers continue to explore the possibility of a “male birth control pill,” as yet there is not one available.
Condom The male condom is a sheath, gener- ally made of latex rubber (though some brands are made from natural materials such as animal gut), that fits tightly over the erect penis and, when put on properly, has a reservoir (bubble) at the tip to contain the ejaculate. The condom is one of the earliest known methods of contraception, with ref- erences to condomlike devices made from animal gut and other natural materials in texts dating to ancient cultures. Today there are numerous styles of condoms, some that include spermicides and others that contain lubricants.
contraception 99 No No No Yes No Limited Yes No No No Limited No Shared Abstinence Rhythm Withdrawal Male Condom Vasectomy Female Diaphragm
Female condom (intrav- aginal sheath)
Implanted or injected contraceptive
Intrauterine device (IUD)
Oral contraceptive (birth control pill)
Spermicides
Tubal ligation or hysterec- tomy
Requires planning of sex- ual activity
Requires planning of sex- ual activity
Requires interruption of sexual activity
Requires condom avail- ability and proper use No requirements after
two negative sperm counts
Requires fitting by health care professional and preparation with sper- micide and insertion prior to sexual activity Requires preparation with
spermicide and inser- tion prior to sexual activity
Extended contraception; requires physician visit and insertion or injec- tion
Physician must insert; requires no attention after insertion Requires prescription
from physician, remem- ber to take pill daily; possible hormonal side effects
Require application before sexual activity No requirements after
healing from surgery; sterility is permanent
Low to moderate Low to moderate Low
Moderate alone; high in combination with sper- micide
High
Moderate alone; high in combination with sper- micide
Moderate alone; high in combination with sper- micide
High
High
High
Low alone; moderate to high in combination with other methods High