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Endoscopy vs Colonoscopy – What’s the Difference?

endoscopy vs colonoscopy

Endoscopy is a nonsurgical procedure to examine the digestive tract.  A colonoscopy is a type of endoscopy that examines the lower part of your digestive tract which includes the rectum and large intestine (colon). Oftentimes, when people use the term endoscopy, they are actually referring to an esophagogastroduodenoscopy (EGD). You may hear the term upper endoscopy, EGD, and endoscopy used interchangeably. Like a colonoscopy, an EGD is a type of endoscopy.


Most endoscopy procedures use an instrument called an endoscope.  An endoscope is a long, thin, flexible tube with a camera on the end.  The endoscope provides high-quality images of your throat, esophagus, stomach, rectum, and colon.

One exception to using an endoscope for endoscopy is when doctors need to view the small intestine.  Due to its size and position in the digestive tract, doctors use a wireless capsule camera. It’s essentially a camera inside a pill capsule that patients swallow.  As it moves along the digestive tract, it takes pictures which are recorded using a device worn around the patient’s waist. During the journey, the capsule can transmit as many as 50,000 to 60,000 images of the digestive tract.

To read more about all of our endoscopic procedures, visit our Advanced Endoscopy information page.


Considered the gold standard of colorectal cancer detection, colonoscopies allow us to take a detailed look at your rectum and entire large intestine (colon). Because all colorectal cancer begins as precancerous polyps, removing these polyps during a colonoscopy can completely prevent this deadly disease.

By age 45, everyone should have a screening colonoscopy.

Endoscopy vs Colonoscopy: Key Differences

The main difference between an endoscopy (EGD) and a colonoscopy lies in the areas they examine. While an endoscopy focuses on the upper gastrointestinal (GI) tract—including the esophagus, stomach, and first part of the small intestine (duodenum)—a colonoscopy specifically targets the lower GI tract, particularly the large intestine and rectum.

Preparation for the procedures also varies. Endoscopy requires fasting for 6-8 hours before the procedure, while colonoscopy requires a more thorough bowel preparation beginning the night before the procedure. This ensures that the colon is completely clean so a more thorough and accurate examination can be done. 

The sedation levels during the procedures may also differ. Endoscopies can be performed with minimal sedation, while colonoscopies typically require general anesthesia to ensure the patient is comfortable and relaxed throughout the process.

Endoscopy vs Colonoscopy Benefits 

There are several reasons a physician may recommend an endoscopy or colonoscopy. While colonoscopy is most commonly performed to screen for colon cancer, endoscopies are usually recommended to investigate problems with the upper intestinal tract. 

Endoscopy benefits:

  • Can be done as an outpatient procedure with minimal sedation.
  • Can diagnose and treat certain conditions, such as ulcers and gastroesophageal reflux disease (GERD), during the procedure.
  • Minimal recovery time, with most patients resuming normal activities shortly after the procedure.

Colonoscopy benefits:

  • Considered the most accurate screening method for detecting colorectal cancer and precancerous polyps.
  • Allows for the removal of polyps during the procedure, reducing the risk of colorectal cancer development.
  • Can diagnose and treat conditions such as diverticulitis, Crohn’s disease, and ulcerative colitis.

When to Schedule an Endoscopy vs Colonoscopy

Both procedures serve essential roles in diagnosing and managing various gastrointestinal conditions. While endoscopy is a more general tool used for the upper GI tract, colonoscopy is specifically designed to investigate the lower GI tract and is a vital screening tool for colorectal cancer. 

Some common reasons you may need to schedule an endoscopy is for conditions like chronic heartburn or stomach pain. Your doctor may recommend an EGD as part of your evaluation. 

Colonoscopy, on the other hand, should be scheduled by anyone that is age 45 or older. Its importance in preventing colon cancer cannot be understated. After your first colonoscopy at age 45, your doctor will help you determine when you should have your next one. 

Learn more about how a colonoscopy can save your life.

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