One of the most important steps in colonoscopy is patient bowel preparation to ensure that the colon is thoroughly cleaned before the exam so that the doctor can clearly see the entire colon to look for abnormalities.
This week, Dr. Mehmet Oz explains in the TIME magazine article “What I Learned from My Cancer Scare,” how his poor bowel preparation prior to his colonoscopy screening for colorectal cancer required him to undergo an early repeat exam after a polyp was found and how he then put off that repeat exam despite the recommendations of his doctor. The American Society for Gastrointestinal Endoscopy (ASGE), which represents the doctors who specialize in colonoscopy and colorectal cancer screening, encourages people undergoing colonoscopy to follow bowel preparation instructions carefully and to undergo follow-up exams for colorectal cancer prevention as recommended.
“Colorectal cancer is one of the most preventable cancers because the majority of colorectal cancers arise from precancerous growths in the colon called polyps, which can be found during a colonoscopy screening exam and removed before they turn into cancer,” said Gregory G. Ginsberg, MD, FASGE, president, American Society for Gastrointestinal Endoscopy. “Prepping for colonoscopy is not fun. Like many Americans, Dr. Oz did not follow the preparation instructions carefully prior to his colonoscopy, so because his colon was not thoroughly cleaned, the exam was considered unsatisfactory and his doctor recommended that he return in three months, rather than several years, to repeat the exam in case other polyps were missed. We commend Dr. Oz for highlighting the importance of colorectal cancer screening and for encouraging patients to follow bowel preparation instructions and follow-up exam recommendations as directed. A quality preparation for colonoscopy and appropriate follow-up exams save lives.”
Preparing for a Colonoscopy
It is extremely important that the colon be satisfactorily cleaned before colonoscopy. This will let the doctor see any abnormalities, such as colon polyps, during the procedure. Polyps are small growths in the colon that could later turn into cancer. Cleansing the colon before a colonoscopy is called bowel preparation, or “prep.” It involves taking medication that causes diarrhea, emptying the colon. The medication is taken by mouth, and comes in liquid or tablet form. Patients will also need to change what they eat during the day or two before the colonoscopy.
The doctor will prescribe the type of bowel prep that is best for each patient and will provide specific instructions. In general, the patients can expect the doctor asking to change diet and eating habits at least one day before your colonoscopy. Diet restrictions usually include limiting the diet to “clear liquids,” such as clear broth, tea, gelatin desserts, ginger ale, sherbet, and clear fruit juices, such as apple juice. As part of the prep, the doctor will usually ask his patient to drink more liquids than normal. This helps avoiding dehydration during bowel prep.
To help the doctor, patients are asked to tell their doctor what medications they are taking, especially aspirin products, arthritis medications, anticoagulants (blood thinners such as warfarin or heparin), clopidogrel, insulin or iron products. Most medications can be continued. Some can interfere with either the prep or the colonoscopy.
Cancer from a precancerous polyp
Colorectal cancer is found in the colon or the rectum, and usually develops very slowly, over a period of years, from a precancerous polyp. A polyp is an abnormal growth of the tissue that lines the colon or rectum. The two main types of polyps are the adenomatous polyp and the hyperplastic polyp. An adenomatous polyp is a benign, precancerous growth that, if not removed, has the greatest risk of becoming cancer; a hyperplastic polyp is a benign growth with no potential to develop into cancer.
Screening is important
Because colorectal cancer develops slowly, screening for the disease is especially important as it allows the doctor to locate and remove polyps before they turn into cancer. For individuals at average risk, the ASGE recommends colonoscopy screening beginning at age 50 and repeating the procedure every ten years after a normal exam. For individuals with a family history, screening should begin at age 40, or at an age as recommended by their doctor. Colonoscopy is a particularly valuable method of colorectal cancer screening because it is the only method that allows for the detection and removal of precancerous polyps during the same exam and before the polyps turn into cancer, thereby preventing the colorectal cancer from occurring.
Removal of an adenomatous polyp prevents that polyp from becoming cancerous, but the patient is still at risk to develop new polyps in the colon and will require more frequent follow-up exams. If the patient has a family history of colorectal cancer, the interval for their follow-up exam may be shortened. After a colonoscopy exam, the doctor will recommend when the patient should return for another colonoscopy.
Colorectal cancer is often present in people without symptoms, making prevention and screening for colorectal cancer very important. A polyp may be found and removed even before it becomes cancerous or presents with symptoms; once symptoms appear, a colonoscopy is performed to aid in diagnosis, rather than screen for disease. The following signs or symptoms, however, might indicate colorectal cancer: blood in stools, narrower than normal stools, unexplained abdominal pain, unexplained change in bowel habits, unexplained anemia, and unexplained weight loss. These symptoms may be caused by other benign diseases such as hemorrhoids, inflammation in the colon or irritable bowel syndrome. The presence of these symptoms for more than a few days is an indication to talk with a gastrointestinal specialist about these symptoms and the patient’s family history.
For more information:
– Brochure: Understanding Bowel Preparation and Understanding Colonoscopy (Patient education)
– Video: what to expect before, during and after a colonoscopy (Patient education)
– American Society for Gastrointestinal Endoscopy’s colorectal cancer awareness website (Patient education and information) .
American Society for Gastrointestinal Endoscopy’s “Peter and Polly Polyp” Facebook page