Many patients who struggle with chronic gastrointestinal symptoms have a colonoscopy done with their gastroenterologist. A colonoscopy is an exam where a doctor places a small camera with a light inside the rectum to visualize the walls of the colon. This procedure can diagnose or rule out many conditions, including: colon polyps and cancer, diverticulitis, colitis (whether due to inflammatory bowel disease or other causes like infection), narrowing of the colon walls, and large bowel obstructions. Many of these conditions are quite serious, and if found need immediate treatment.
As a naturopathic doctor, I think colonoscopies are a vitally important exam for many patients. But the major problem with this test is this: patients are often told by their gastroenterology clinic that “everything is normal” if the colonoscopy comes back clean. But in reality, all we know is that the conditions above are not present. There is a long list of intestinal diseases that CANNOT be seen on a colonoscopy that likely have not been ruled out yet. As I tell my patients, each medical exam or test is only good at ruling out the specific diseases it has the ability test for. So — each negative result only means we know those specific conditions don’t exist. But when you are talking about GI imaging/testing, there is an enormous number of exams that can be ordered, and each one typically only evaluates for 1-2 conditions at a time. If no diagnosis has been found, it is likely that the right test has not been ordered yet.
So which conditions do I commonly in my practice see that have normal colonoscopy reports? Here are my top three:
- Diseases that occur in the small intestine: The camera used in a colonoscopy can typically get all the way through the large intestine, but it does not go into the small intestine at all. The small intestine is about 20-25 feet long –- which is a lot of area that is not getting examined! A better exam for the small intestine is an upper endoscopy, though even this test only looks at the very first part of the small intestine. Patients with Celiac disease, colitis/Crohn/s in the small intestine, or small intestinal cancers or polyps will all have normal colonoscopies.
- Many infectious diseases of the GI tract: Patients are often surprised to hear that a colonoscopy camera cannot visualize any kind of “bugs” in the intestinal tract. They are also often told that the prep for the colonoscopy will flush out much of their intestinal flora. They then mistake this to mean that the prep will also kill any intestinal infection. Colonoscopy prep –while it can cause some alterations to our ratio of good/bad bacteria– is NOT an antibiotic. Nor is it an antifungal or antiviral. Infections are persistent and will not be wiped out with magnesium citrate bowel prep alone. And infections are too microscopic for a camera to see. So, patients with SIBO (small intestinal bacterial overgrowth), large intestinal dysbiosis/infections, and intestinal candida will all have normal colonoscopies.
- Food intolerance reactions: Chronic food intolerances cause no noticeable changes to the lining of the colon. In some cases, the inflammation caused by these reactions can be seen in the small intestine or stomach lining, though the results will still be non-specific. The only way to test for food intolerances is with specific blood antigen testing. I use US Biotek for all food intolerance testing at my office and find the results to be reliable, reproducible, and extremely helpful for the subset of patients who struggle with chronic food reactions.
Colonoscopies and upper endoscopies are extremely important examinations. They rule out many disease processes and aid in the diagnosis of many others. As a naturopathic doctor, my only qualm with these exams is what patients are sometimes told or led to believe when test results are normal – “Everything looks good”, “There is nothing wrong with you”, “It’s just IBS”. While sometimes everything is normal, many other times symptomatic patients are left without any sort of help for their yet-to-be-diagnosed condition. My advice: if you struggle with chronic GI symptoms, don’t let a normal colonoscopy deter you from continuing to seek a diagnosis and proper treatment. Often the right test is out there, you just haven’t had it yet.
Dr. Katie Nuckolls is a naturopathic physician and owner of Thrive GI: Natural Digestive Medicine in Vancouver, Washington. She currently sees patients that live in Washington, Oregon, and Arizona using telemedicine. For more information, visit our contact page or schedule a free 15-minute consultation online.