Endoscopy and colonoscopy are both minimally invasive procedures using similar tools. However, they have different purposes. Doctors use endoscopy in a wide range of testing throughout the body, but they perform a colonoscopy specifically to view the colon.

An endoscopy is a minimally invasive procedure that lets doctors view organs in the body and operate on them without making standard surgical incisions.

In fact, endoscopies can sometimes be done without an incision at all. This is because an endoscopy uses a very thin tube called an endoscope, with a camera attached to one end. A doctor can insert this tube through a tiny incision or an opening in the body, such as the mouth.

A colonoscopy is a kind of endoscopy procedure that can examine the colon. A thin, flexible tube known as a colonoscope is inserted through the anus and into the colon. It never requires an incision. This procedure is used to screen and diagnose colon cancer and look for causes of many digestive issues.

These two procedures are very similar, but they have distinct and important uses in diagnosing cancer and other conditions.

An endoscopy is a procedure that involves the use of an instrument called an endoscope — a thin, flexible tube with a small camera attached to one end.

It allows a doctor to work inside your body without a traditional surgical incision. The doctor can insert the endoscope via an opening in the body, such as the mouth, or through a small incision.

Once inserted, the camera allows the doctor to visually examine specific organs, blood vessels, muscles, or bones. The doctor can then use small instruments attached to the endoscope to remove tissue or perform surgical procedures.

What it diagnoses

There are multiple uses for endoscopy. It can help a doctor get clear images of what’s happening inside your body. If you need a biopsy, the doctor can also take a sample of tissue during the procedure.

A doctor might order an endoscopy if they suspect:

Preparation can vary slightly depending on the type of endoscopy you’re having. Some endoscopies require small incisions, while others do not.

You’ll likely be asked not to eat solid foods on the day of your procedure. You might be asked to stop taking certain medications as well, especially medications that affect bleeding, such as anticoagulants. If you’re having an endoscopy for gastrointestinal issues, your doctor might give you laxatives or enemas the night before to help clear your system for the procedure.

Most endoscopies are outpatient procedures. You’ll often receive some form of sedation or anesthesia so that you don’t feel any pain. The exact type depends on the procedure and your preferences. You can discuss this with your doctor before your endoscopy.

The length of the procedure will also depend on the exact type of endoscopy you’re having. For instance, it will take longer if an incision is needed, or if the surgeon is also removing tissue for a biopsy. Your doctor will go over these details with you before the procedure.


Endoscopies are less invasive and have fewer risks than traditional surgery. However, like all medical procedures, there are some risks.

Risks may include:

  • bleeding
  • infection
  • pain
  • redness and swelling at the incision site
  • a negative reaction to sedative or anesthesia

Rarely, more serious complications can occur. These include:

  • organ damage
  • chest pain
  • trauma at the opening or incision site
  • persistent pain

Risks can vary depending on the specific type of endoscopy you have. Your doctor can explain the risks associated with your procedure.

A colonoscopy is a procedure a doctor uses to look for issues in your colon (large intestine). It’s often used as a tool to screen for colon cancer because it lets doctors see the inside of the colon.

According to the American College of Surgeons, about 90% of colon tumors or polyps can be found using colonoscopies.

The procedure involves the use of a tool called a colonoscope — a thin tube with a light and camera attached to one end. During a colonoscopy, a doctor inserts the tube through the anus and into the colon.

This allows the doctor to get a detailed view of the inside of your colon. In some cases, they might remove tissue for a biopsy or remove atypical tissue, such as colon polyps.

What it diagnoses

Colonoscopies are used as a colon cancer screening and diagnostic tool. Your doctor might also order one if you have:

Preparing for a colonoscopy typically involves 24 to 72 hours of bowel preparation. You’ll be asked to stick to a clear liquid diet during this time. A doctor will give you exact instructions, but a standard clear liquid diet typically consists of:

  • water
  • clear broth
  • coffee or tea without cream or milk
  • sports drinks
  • pulp-free juices

The doctor might also give you a laxative or enema to make sure your system is cleaned out.

It’s important to tell the doctor about any medications you take. You’ll likely be instructed to stop taking certain medications, including iron supplements and some diabetes medications, while you prepare.

Colonoscopies are typically outpatient procedures. You’ll be given pain medication and some form of sedative or anesthesia to ensure you’re comfortable during the colonoscopy. You can discuss your anesthesia preferences with the doctor beforehand.

You’ll lie on your side for the procedure, and the colonoscope will be slowly and carefully inserted through your anus into your colon. Once the colonoscope is in position, your doctor will use carbon dioxide to inflate your colon.

They’ll then examine your colon closely and may take a tissue sample or remove polyps. Typically, a colonoscopy takes between 15 minutes and 1 hour.


A colonoscopy is considered safe and low risk. However, rare complications can occur.

These include:

  • a negative reaction to sedative or anesthesia
  • perforation of the rectal wall
  • perforation of the colon
  • bleeding from the biopsy site

Colonoscopy and colon cancer

The U.S. Preventive Services Task Force recommends a colonoscopy as a colon cancer screening method beginning at age 50.

Screening should be once every 10 years and should continue until you reach age 75. Adults between the ages of 75 and 85 should ask their doctor about screening.

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You may be at a higher risk for colon cancer if you have:

If you’re at an increased risk for colon cancer, you may want to get screened before you turn 45 years old or more often than the standard recommendation. Talk with your doctor about your personal risk level and when you should be screened.

Endoscopies and colonoscopies are similar procedures that help doctors see inside your body without the need for traditional surgery. These minimally invasive procedures can also be used to collect tissue samples for biopsies and perform small surgical operations.

An endoscopy is used in a wide range of testing throughout the body. A colonoscopy is specifically used to look at the colon and is important for colon cancer screenings.