Colonoscopy

Introduction | Anatomy

Introduction

A colonoscopy is a procedure that uses a scope to view the inside lining of the entire colon. A scope is a long thin tube with a light and a viewing instrument that sends images to a monitor. The scope allows a doctor to examine the inside of your colon for cancer, polyps, and disease. A tissue sample or biopsy can be taken with the scope. A colonoscopy is an outpatient procedure. You will receive medication to relax you prior to the test.

Test Use

A colonoscopy may be ordered for several reasons. It most frequently is used as a screening tool for colon polyps or colon cancer. A colonoscopy may also be used to identify digestive or inflammatory disease. It is helpful for determining the cause of bleeding, pain, or changes in bowel habits. Additionally, a scope is used for taking photographs, obtaining tissue samples, surgically removing polyps, or specialized laser surgeries.

PREPARATION

A colonoscopy is an outpatient procedure that can be performed at a doctor’s office or a hospital. Another person will need to drive you home because you will receive sedation medication for the procedure. Preparation instructions for a colonoscopy generally consist of methods to empty or clean your bowel prior to the test including the use of laxatives, enemas, or a liquid diet. You should not eat or drink on the night before your test. Your doctor will provide you with specific instructions.

THE PROCEDURE

You will wear an examination gown for your colonoscopy. The healthcare staff will monitor your blood pressure, heart rate, breathing rate, and temperature during the test. You will receive pain-relieving medication and a sedative through an IV line. The medication will relax you and make you feel drowsy.

A digital rectal examination may be performed before the test. You will lie on your left side with your knees bent for the procedure.

Your doctor will carefully insert the scope into your colon through your anus. Air will be inserted to open the folds of the colon to provide a better view. Your doctor will gently and slowly advance the scope into your colon. You may need to change positions during the procedure to allow your doctor to best place the scope.

The procedure may cause temporary discomfort. It is common to experience gas during and after a colonoscopy. You may feel nauseous, bloated, and drowsy after the procedure. Your doctor will instruct you on how to increase your food and liquid intake. Your doctor will also discuss unexpected symptoms related to the test that may occur and a plan to address them.

Your doctor will review the results of your colonoscopy with you at a follow-up appointment. It may take time for biopsy results to be received. If abnormal results were found during your test, your doctor will discuss treatment options with you.

Anatomy

Your body absorbs nutrients and removes waste products via your digestive system. Whenever you eat and drink, food travels through your digestive system for processing. As water from the waste product is absorbed, the product becomes more solid and forms a stool or feces. It is eventually eliminated from your body when you have a bowel movement.

After you swallow food, it moves through your esophagus and into your stomach. Chemicals in your stomach break down the food into a liquid form. The processed liquid travels from your stomach to your small intestine. Your small intestine breaks down the liquid even further so that your body can absorb the nutrients from the food you ate. The remaining waste products from the small intestine travel to the large intestine.

Your large intestine, also called the large bowel, is a tube that is about 5 feet long and 3 or 4 inches around. The first part of the large intestine is the colon. The large intestine is divided into sections, including the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canal, and anus. The appendix is located on the cecum, but it does not serve a purpose in the digestive process.

The first part of the colon absorbs water and nutrients from the waste products that come from the small intestine. As the colon absorbs water from the waste product, the product becomes more solid and forms a stool. The large intestine moves the stool through the large intestine into the sigmoid colon, where it may be stored before being traveling to the rectum. The rectum is the final 6-inch section of your large intestine. No significant nutrient absorption occurs in the rectum or anal canal. From the rectum, the stool moves through the anal canal. It passes out of your body through your anus when you have a bowel movement.

This information is intended for educational and informational purposes only. It should not be used in place of an individual consultation or examination or replace the advice of your health care professional and should not be relied upon to determine diagnosis or course of treatment.

The iHealthSpot patient education library was written collaboratively by the iHealthSpot editorial team which includes Senior Medical Authors Dr. Mary Car-Blanchard, OTD/OTR/L and Valerie K. Clark, and the following editorial advisors: Steve Meadows, MD, Ernie F. Soto, DDS, Ronald J. Glatzer, MD, Jonathan Rosenberg, MD, Christopher M. Nolte, MD, David Applebaum, MD, Jonathan M. Tarrash, MD, and Paula Soto, RN/BSN. This content complies with the HONcode standard for trustworthy health information. The library commenced development on September 1, 2005 with the latest update/addition on April 13th, 2016. For information on iHealthSpot’s other services including medical website design, visit www.iHealthSpot.com.