There aren’t many everyday medical procedures that provoke as much anxiety as a colonoscopy. And for good reason. Although relatively risk free, let’s face it––it’s invasive. Still, if you’re in a high-risk category for colon cancer, it’s the best early detector available. Although in the United States colorectal cancer is the fourth-most common cancer and the second leading cause of cancer-related deaths, the death rate has been declining, thanks in part to early detection by colonoscopies. Worldwide, there are nearly two million cases of colorectal cancer every year. So if you’re scheduled for a procedure, what do you need to do to prepare? Here’s a brief guide that’s all about colonoscopies.
Long History of Long Tubes
Believe it or not, the endoscopes used in today’s colonoscopies are similar to those first developed in the 1800s. Long before X-rays and other advances, doctors used flexible tubes to reveal hidden areas of our bodies. The open-tube endoscope for examinations of the bladder and urethra was created in 1853 by French urologist Antonin Jean Desormeaux who called it “l’endoscopie,” He was followed almost 50 years later by George Kelling who in 1901 first endoscopically examined the peritoneal cavity. He called the procedure “celioscopy.”
Room-sized computers wouldn’t be very helpful for procedures that required insertion of a tube into the body. It took the arrival of video computer chips which allowed magnification of images captured during laparoscopic surgery in 1986 to make endoscopic procedures commonplace. That’s because modern endoscopes feature lights and cameras. In the 21st century, they even utilize artificial intelligence and automatic polyp detection systems to improve detection of colon polyps––the primary cause of colon cancer.
Colonoscopies are used to diagnose and treat conditions that affect the colon, ileum (the bottom section of the small intestine), and the rectum. Guidance on when and how often to get the procedure varies. Previously, the consensus recommendation was to start colorectal cancer screening at the age of 50, however, more recently, organizations including The American Cancer Society recommends colorectal cancer screening for people over the age of 45. However, if you have a family history of either polyps or colorectal cancer, you may need to have the procedure at a younger age.
There are different methods for screening for colorectal cancer including colonoscopy, virtual colonoscopy, or a stool test. The colonoscopy remains the gold standard for screening for colon cancer. If this is not an option due to specific medical circumstances, then a virtual colonoscopy provides a non-invasive way of examining the rectum and colon from outside of your body. Also called a computerized tomography (CT) colonography, it can detect ulcers, polyps, and cancer–but some smaller polyps can go undetected and occasionally leftover stool sediment may be read as a polyp. Sometimes actual colonoscopies are required after a virtual version returns concerning or inconclusive results. The colonoscopy remains the only way to examine the inside of the entire colon and remove polyp(s). This makes it the only preventative modality and provides the most information.
To prepare for the procedure you’ll need to cleanse your colon––abstaining from solid foods for at least one day prior. Your diet will be limited to such things as fat-free bouillon or broth, plain coffee, and water. You should also avoid drinking red beverages such as red juices or jello as this can be mistaken for blood by the examiner. You will then need to take a laxative preparation overnight to clean out the colon from any stool. Many options for laxative regimens exist and this will be advised by your physician. The bottom line is that you should be completely ‘clear’ and cleaned out when completing this.
The colonoscopy may take place at a medical center or hospital. Upon arrival, you’ll be asked to disrobe completely and don a gown. You’ll be given sedation to ensure you are comfortable during the procedure. Lying on your left side with your knees pulled up to your chest, the doctor will guide the endoscope through your anus and into your rectum and colon. The scope will also use air or often CO2 to inflate your large intestine. This will improve your doctor’s view as images are sent to a monitor. The procedure typically takes about 20-30 minutes but can take longer in certain circumstances in which the doctor may adjust you several times to change the scope’s viewpoint. The camera will capture images of your colon and any problematic polyps. These polyps will be removed during the procedure. The colonoscopy is thus not only a way to detect precancerous polyps but also remove them and prevent the development of cancer. It is also a way to diagnose colon cancer and get samples to guide future treatment.
Afterward, you may experience cramping or gas. You’ll need to have someone drive you home. Recovery is normally quick and easy. Depending what is found during the colonoscopy, will determine when your next colonoscopy should be. This is dependent on the number of polyps, the size, and the morphology of the polyps. Having a suboptimal preparation where the gastroenterologist isn’t able to confidently detect polyps can also factor into an earlier screening interval.
Written by John Bankston
- What Is Colorectal Cancer?
- Colorectal cancer statistics
- Virtual Colonoscopy
- A brief history of endoscopy, laparoscopy, and laparoscopic surgery
- Real-time automatic detection system increases colonoscopic polyp and adenoma detection rates: a prospective randomized controlled study
- American Cancer Society Guideline for Colorectal Cancer Screening