A colonoscopy involves a gastroenterologist using a camera attached to a colonoscope—a thin, flexible tube—to take photos or video of the inner lining of your colon, also called the large intestine, the lower part of the small intestine, and the rectum.
During a colonoscopy, your doctor may find ulcers, colon polyps, tumors, and inflamed or bleeding areas; collect tissue samples for biopsy and abnormal growths; and to screen for growths or polyps that can potentially lead to colorectal cancer. Although colorectal cancer is the second most common cause of cancer deaths in the country, it has a high cure rate—over 95%—if detected early.
What Can a Colonscopy Find?
There are a range of conditions and issues that a colonoscopy can help diagnose and treat. They include:
- Colorectal cancer or polyps
- Blood in the stool or rectal bleeding
- Dark or black stools
- Chronic diarrhea
- Iron deficiency anemia
- Sudden, unexplained weight loss
- Abnormal results from a CT scan, MRI, virtual colonoscopy, stool test, or barium enema
- Inflammatory bowel disease (IBD)
- Long-term, unexplained belly pain
Who Should Have a Colonoscopy?
There are a variety of guidelines for colonoscopy. In general, you should have a colonoscopy if you are:
- Age 50 and older with a normal risk for colorectal cancer
- At a higher risk of colorectal cancer (your doctor may recommend earlier or more frequent testing.) You may be at higher risk if you have:
- Had polyps or previous colorectal cancer
- A history of inflammatory bowel disease, such as ulcerative colitis or Crohn’s disease
- One or more family members who has had colon cancer or advanced colon polyps
- Inherited gene defects such as Familial Adenomatous Polyposis (FAP) or Hereditary Non-Polyposis Colon Cancer (HNPCC)
- Certain racial and ethnic background; African Americans and Jews of Eastern European descent (Ashkenazi Jews)
Additional Tests for the Colon
In addition to a colonoscopy, there are several other tests that can help determine the health of your digestive system, including sigmoidoscopy (which shows only the rectum and the lower part of the colon); stool tests; and computed tomographic colonography. The use depends on your risk, your needs, and your doctor’s specific recommendation.
Talk to your primary care doctor about scheduling your colonoscopy. You can learn more about conditions we treat, procedures we offer and instructions for preparing for your procedure at Mary Greeley Medical Center on our Gastroenterology (GI) Services page.