USNEWS：不喜欢做结肠镜检查的人还有6种新选择！

In fact, only about 50 percent of people follow their doctor’s orders to get a colonoscopy. But not getting tested can have deadly consequences. According to the American Cancer Society, colorectal cancer is second only to lung and bronchial cancers in cancer-related deaths, claiming about 50,000 lives each year. But the good news, experts say, is that most cases of colon cancer can be prevented through screening and adopting healthy lifestyle habits.

The U.S. Preventive Services Task Force recommends adults 50 to 75 years old with no risk factors for CRC have a colonoscopy once every 10 years to screen for the disease. So, if most colon cancer is preventable or at least treatable, why are so many people skipping a colonoscopy? Perhaps because it “requires bowel preparation, and most people will probably tell you that preparation is worse than the actual procedure,” says Dr. Nicholas J. Petrelli, medical director at Christiana Care Health System’s Helen F. Graham Cancer Center and Research Institute.

The day before the procedure, you may have to adopt a clear liquid diet and take a series of special laxatives to completely empty out your bowel. “The other thing is that people have to be sedated for the colonoscopy, they need a driver and need to take off work,” says Dr. Eduardo Vilar-Sanchez, assistant professor of clinical cancer prevention at MD Anderson Cancer Center. Rather skip the colonoscopy? Here are six other ways to screen for colon cancer; half are radiological exams, while the others use samples from your stool.

In this procedure, a technician inserts a small tube into the first 2 inches of the rectum and pumps air into the colon for better visualization. Images of the colon are captured outside the body using a CT scanner, so you don’t have to be put to sleep.

Drawbacks: You still have to empty out your entire colon beforehand, and if the doctor finds a polyp or another abnormality, you’ll need a traditional colonoscopy to take a closer look and have any abnormal tissue biopsied or removed. You also need to be retested every five years.

Unlike a traditional colonoscopy or CT colonoscopy, you won’t need laxatives or to be sedated before this test. Since the procedure only looks at the left side of the colon, your doctor will likely have you use an enema to clean out the lower part of the colon and the rectum.

Drawbacks: You must retest every five years, and your doctor can’t check the right side of your colon. “If you have any findings on the left side that may be indicative of risk, you’ll have to follow up with full colonoscopy,” Petrelli says.

Also called a lower gastrointestinal exam, this is one of the oldest CRC screening tests. Abnormalities in the colon and rectum become easier to see in an X-ray after you use an enema containing a barium-based dye.

Drawbacks: Your doctor will likely put you on a non-dairy, liquid diet the day before the test. Be prepared to drink a lot of extra liquid and use laxatives or an enema per your doctor’s orders. You’ll need to get the test every five years.

This home-based test detects blood in your stool by interacting with an iron-binding protein found in red blood cells called heme. (Guaiac, a plant substance, is used to coat the test cards.) You don’t have to be sedated, take laxatives or take off work.

Drawbacks: You have to collect samples from three different bowel movements, which you smear on a card and mail in for evaluation. Because this test also detects blood found and gives false positives, your doctor will probably have you avoid certain foods before you get the exam. And, you may have to get this test every year.

Another type of FOBT, the FIT doesn’t require laxatives, enemas, sedation or vacation time. However, unlike the guaiac FOBT, you only need to collect one sample and can eat whatever you want beforehand.

Drawbacks: Minor stomach bleeding caused by certain medications can give false positives results. But according to Dr. John B. Kisiel, a gastroenterologist at the Mayo Clinic, those instances are low. “The false positive rate is only about 4 to 6 percent, but if you have a positive screening test, then you’ll need a diagnostic colonoscopy,” he says.

Approved by the Food and Drug Administration in 2014, this at-home test checks for DNA mutations that are precancerous, cancerous or otherwise abnormal. No laxatives or enemas are required. Users collect a stool sample while sitting on the toilet, which they then prepare, preserve and mail in for analysis. Vilar-Sanchez says the test is more sensitive than FIT and FOBT but has two major drawbacks: “A positive test must be confirmed with colonoscopy. Negative tests must be repeated, but because the test is new, we don’t know how often that should be yet.”

While experts generally agree none of these alternative tests are particularly better than another, giving people options makes them more likely to get tested. “When we give patients a choice, the overall screening is higher,” Kisiel says. “Patients are more likely to get screened when they are offered a choice of tests.”