Endoscopy vs. Colonoscopy: Know the Difference

Published November 9, 2020
An endoscopy is a procedure that involves the insertion of a lit, flexible tube, known as an endoscope, through one of your orifices to visualize or view at something inside your body.
What are the basic definitions of endoscopy and colonoscopy?
What we commonly refer to as an endoscopy is actually an “upper endoscopy,” which is a type of endoscopy used to examine the upper digestive system. In this procedure, specialists in diseases of the digestive system (gastroenterologists) insert the endoscope through the mouth, passing through the esophagus to reach the location of interest.
A colonoscopy is essentially a type of endoscopy. This procedure involves the insertion of an endoscope, usually through the rectum, to view the rectum, the lining of the large intestine, and colon.
When you need an upper endoscopy or colonoscopy
Besides which parts each procedure examines, they differ in what symptoms they address or look for.
Upper endoscopies address several problems, the first of which is with the upper digestive tract. This includes symptoms like:
- abdominal or chest pain
- nausea
- bleeding
- heartburn
- vomiting
- trouble swallowing
Upper endoscopies can be performed as part of an endoscopic ultrasound. An endoscopic ultrasound assesses the digestive tract along with nearby organs in the pancreas, liver, and lymph nodes by using a special endoscope, which uses high-frequency sound waves to produce detailed images of the organs. This procedure effectively assesses the extent of cancers, tumors, and other abnormalities to the organs involved.
Another application of upper endoscopies is for taking biopsy samples. When doctors find potential abnormalities in tissues, they take tissue samples or biopsies to assess them better. Attaching forceps to the endoscope allows them to take samples from the esophagus, stomach, or small intestine.
Colonoscopies focus on problems and symptoms in the lower digestive tract, including the large intestine (colon) and rectum. A gastroenterologist might apply this to investigate the following symptoms:
- abdominal pain
- rectal bleeding
- chronic constipation
- chronic diarrhea
- other intestinal problems
Colonoscopies also look for signs of colorectal cancer. One of the risk factors associated with this cancer is age, as the risk increases along with it. Once you reach the age of 50, given that you are at an average risk factor, experts recommend having a colonoscopy every few years to screen for this type of cancer.
Colon polyp removal is also one of the applications of colonoscopies. Colon polyps are small clumps of cells that form on the lining of the colon. While most of them are typically harmless, some of these may eventually develop into colon cancer. Most of the time, colon polyps won’t show any symptoms, requiring a colonoscopy to examine the colon’s situation closely. If you have a family history of colon cancer, you’ll want to have regular screening even before the age of 50.

Preparation
Because you’re dealing with different organs in the body, the preparation drastically differs too.
Before an upper endoscopy, patients are required not to eat anything six hours prior to the operation. This ensures that the stomach will be empty for a safe and complete examination. Before scheduling the procedure, the patient will also need to provide the doctor with details of any medication he or she is taking. Doing so will give the doctor ample time to advise the patient to stop any medication that could complicate the procedure.
Colonoscopy preparations are much more extensive and restrictive than an endoscopy. To ensure a successful and accurate procedure, the patient will need to flush out their colon completely. Typically, this means going on a clear liquid diet for a couple of days, laxatives, enemas, or drinking a large volume of cleansing solutions. The patients must follow these instructions to the tee or risk an incomplete procedure because of residual stool getting in the way of images. Like an endoscopy, the patient will have to inform their attending physician of their medication.
What happens during each procedure
Before both procedures, your doctors will likely explain to you the step-by-step process they will conduct. They’ll explain the possible risks and side effects of the procedure to give you some reassurance should these arise.
Before the endoscopy, nurses may apply a numbing solution to the patient’s throat and intravenously administer sedating medication. Two main types of sedation are practiced: conscious and deep sedation. You will have to lie down on your left side; then, the endoscope is inserted into your mouth, passing through the esophagus, stomach, and duodenum. You should feel no to minimal discomfort with conscious sedation, as the endoscope is designed not to interfere with breathing. An endoscopy will usually take 15 to 30 minutes.
In a colonoscopy, nurses will likely also give sedatives intravenously to reduce or prevent any possible discomfort. The attending doctor will have you lie on your side on the exam table, assuming a position with your knees tucked into your chest. They will then insert the scope into your rectum. As the scope makes its way through your colon, it will pump carbon dioxide to make the images more visible. However, this may give you a feeling of cramping and bloating, inducing the urge to have a bowel movement. Colonoscopies typically last between 30 to 60 minutes.
What to expect after each procedure
After both procedures, you’ll be taken to an area where you can rest. You will need an hour to recover from the sedative, but its effects will last for an entire day, so you will need someone to drive you home. Bloating and cramping may last for a while after the procedure, and you will be passing gas to eliminate discomfort. Do not be alarmed if blood appears in your excrement, as this is a common side effect of this procedure.
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About The Author
Terrence Tan Ting is an industrial engineer by profession but a full time writer by passion. He loves to write about a wide range of topics from many different industries thanks to his undying curiosity.