Colorectal cancer is currently the second deadliest cancer in the United States - but with early detection, survival rates are close to 90%! Cancers which grow in the rectum or the colon are collectively referred to as colorectal cancer. Because tumors in these organs are often asymptomatic, cancer can develop unnoticed for some time. If left undetected, the cancer cells of tumors can metastasize, or spread to nearby organs. At this point, the likelihood of curing the cancer drops significantly. Early detection and removal, however, can often lead to complete recovery! For this reason, from the time they reach 50, adults should begin regular screening for colorectal cancer. Screening involves an annual examination of the rectum and stool. During the examination, a doctor will insert a gloved finger into the rectum to feel for abnormal growths. Stool samples will also be taken to test for occult blood, which is blood that can leak from a tumor to the stool. Occult blood is not visible to the human eye, and is usually detected via chemical color conversions in a lab. If a doctor feels abnormal growths, or if occult blood is found, he or she will usually recommend an internal screening procedure to check for cancer. One such procedure, called a barium enema x-ray, involves delivering an enema containing liquid barium into the rectum. After the enema, an x-ray is taken. In the picture, the barium outlines the intestines in white, while abnormalities appear as dark shadows. As an alternative to x-ray, a sigmoidoscopy or a colonoscopy can be administered to screen for colorectal cancer. Sigmoidoscopy is a screening test where a very thin tube with a light and camera is inserted into the anus, allowing a doctor to clearly see the rectum and lower colon. A total colonoscopy is a similar screening procedure that involves viewing the entire colon. Both sigmoidoscopy and colonoscopy allow a doctor to take a biopsy, or tissue sample, of any areas of the colon or rectum that look abnormal. Biopsies can then be tested in a lab for cancerous changes. As part of regular screening for those over 50, sigmoidoscopies are recommended every five years, while colonoscopies are recommended every ten. On the other hand, more frequent screenings are usually recommended for those who have a history of colorectal cancer in their families, as well as for people who have ulcerative colitis. Because studies have shown that sigmoidoscopies can reduce mortality from cancer, regular screenings just make sense! Colorectal cancer is quite common in the United States. If you have questions or concerns about this disease, please make an appointment to speak with your doctor.