Colonoscopy & Endoscopy Procedure Instructions

Your physician may recommend colonoscopy because of unexplained rectal bleeding, unexplained pain or to evaluate a condition, such as inflammatory bowel disease. Your doctor may also want an evaluation to rule out colon cancer because you or a close relative have a history of colon polyps. This outpatient procedure normally takes 30 to 60 minutes. Before the procedure begins, you’ll receive a sedative that will make you sleepy; most patients don’t feel or remember the procedure afterward. During a colonoscopy, tumors or early cancers can be detected and removed, thereby avoiding surgery and saving lives.

Colonoscopy is a procedure to examine the lining of the entire colon (large bowel) using a flexible instrument, the colonoscope. The primary function of the colon (also called the large intestine) is to absorb fluids from the liquid waste material that comes from the small intestine. When malfunctions occur, the colon can sometimes be the source of abdominal pain, diarrhea or constipation.

“Colon” refers to the large intestine or the last four-to-six feet of the digestive tract. “Oscopy” means “looking into.” Colonoscopy allows your physician to observe the entire length of the colon effectively and generally with little or no discomfort to the patient.

The instrument used in colonoscopy is called a colonoscope. It is a long, thin, flexible tube about twice the diameter of a pencil. There are approximately four channels within the “scope” through which the physician may illuminate, wash, suction, photograph and biopsy the colon. These channels provide the means for removal of most polyps and the cauterization of blood vessels to prevent bleeding.

You have been scheduled for a colonoscopy (examination of your large intestine). You will receive sedatives to make the procedure more comfortable. If you are undergoing an upper endoscopy (examination of the esophagus, stomach, and duodenum) on the same day as your colonoscopy, click here for what to expect for the upper endoscopy portion of your procedure.

It is important that you arrive at the designated time so there is ample time to prepare you for your procedure.

Please adhere to the following guidelines:

  • Please bring your insurance card with you.
  • Leave all valuables at home except your glasses and hearing aids. You or your ride will be responsible for making sure you have them with you upon leaving the unit.
  • Wear casual/comfortable clothing.
  • Bring a small amount of cash (or checkbook) to pay for any copay you may have, or prescription needed after your procedure.
  • It is perfectly appropriate for you to brush your teeth on the day of your procedure. (We encourage you to do so). Please wear your dentures; if we need them removed, we will provide a denture cup for you to store them safely.

Please notify our scheduler if you have special needs or preferences.

  • If you choose to provide us with a copy of your advance directive, we will keep a copy in your chart. However, we will make every effort to resuscitate you in the event of an emergent situation. If you wish to receive additional information regarding this policy, you may contact the facility directly.
  • If your procedure is scheduled at Oregon Endoscopy Center, for your safety if your weight exceeds 350 pounds, or your BMI is ≥ 50, please notify one of our schedulers right away.

Upon arrival, you will be checked in by facility front desk staff.  Once checked in, you will remain in the facility waiting room until called to the admission area.  In the admission area, you will be shown to a bed in a private bay and will change into a procedural gown.  A nurse will listen to your heart and lungs and place an intravenous line in your hand or arm, which is how you will receive medication during the procedure.

  • If you received a phone call before the day of your procedure and have already answered questions about your health history and medications/allergies, a nurse will ask for any updates.
  • If you did not get a phone call, you will be asked questions about your health history, medication use, and medication allergies. We must have a complete list of your medications.

Colonoscopy is performed in a specially equipped private room. Once you have spoken with your doctor, you will be asked to sign your informed consent. A nasal cannula will be placed in your nose that will deliver supplemental oxygen, and you will be connected to the vitals monitor (your pulse, blood pressure, and oxygen level will be monitored continuously throughout the procedure). You will be asked to turn on your left side with your knees drawn up. Your nurse or Certified Registered Nurse Anesthetist (CRNA) will make every effort to ensure you are as comfortable and relaxed as possible by administering sedation medications through your intravenous line. After lubricating the colonoscope and the rectal area, your doctor will gently insert the colonoscope.

During the procedure, it is necessary to inflate the colon with air and carbon dioxide (CO2) to smooth out the normally wrinkled walls of the colon. This combination of air and CO2 will ease the insertion of the scope and improve the view of the colon; at the same time, this may cause you to feel as if you need to have a bowel movement. This feeling of pressure will soon pass.

Your doctor will examine the entire colon.  The colonoscope will be removed slowly as the doctor looks carefully at each area of the colon. If any inflammation or growth is discovered, your doctor may painlessly remove or take a piece (biopsy) of that tissue. Tools can be inserted through the colonoscope, allowing your doctor to remove a tissue sample for testing. This tissue removal or biopsy will only be performed when necessary.

Once the doctor has finished the exam,  the colonoscope will be carefully removed. Colonoscopy can take 20-60 minutes. You will be taken to the recovery area for monitoring after the procedure. Due to the nature of the medications used during the procedure, it is common to remember little or nothing of the procedure or parts of your recovery. You may experience some abdominal pressure or discomfort after the procedure.  This discomfort is likely due to air still in the colon; the best way to get rid of this discomfort is to continue moving around throughout the day, as this will help you pass gas.

After the procedure, a nurse will speak to you about your exam findings and provide you with a detailed report, including pictures, prepared by your doctor. You will need to refer to the report sent home for questions and post-procedure instructions, as you will likely not remember information given to you immediately following the procedure.  Important numbers will be bold or in red on your report. If you need any follow-up procedures, office visits, or medical tests, someone from Eugene Gastroenterology Consultants will contact you to arrange these for you.

Due to the nature of the medications used during the procedure, you MUST have someone transport you home after your procedure. Once you’ve returned home, do not operate any machinery, sign any important legal paperwork, or drive a motor vehicle for at least 24 hours since minor effects of the drugs may persist the rest of the day.

* For female-identifying patients, you will have a female endoscopy technician, nurse, or Certified Registered Nurse Anesthetist (CRNA) in the procedure room with you for the entire procedure.

After Your Procedure

If you also had an endoscopy (EGD), we are interested in knowing whether certain symptoms are associated with acid in the esophagus, we will ask you to keep a written log. On this log, you will mark the time and duration of certain symptoms, such as chest pain, heartburn and cough. You will wear an external receiver that will collect and record data from the sensor. You must return the equipment to Oregon Endoscopy Center after the data has been collected.

If you had polyps removed

Do not take products with aspirin or ibuprofen (Excedrin, Aleve, Motrin, Naprosyn, arthritis medications or Alka-Seltzer) for five days, as this lengthens the time it takes for your blood to coagulate (clot) at the biopsy site(s) and can increase the risk of post-procedure bleeding.

Abdominal gas and bowel function

Immediately following your colonoscopy and possibly for several hours thereafter, you may experience abdominal gas or the sensation of being bloated. This is due to the introduction of air into the colon during the procedure to facilitate the movement of the colonoscope within the large intestine, and to increase visualization by smoothing out the normally wrinkled bowel wall. You will experience increased flatulence (bowel gas), until your colon returns to its normal state (24 hours). Walking can help rid the gas. You may experience loose stool or no stool for up to three days following the procedure. If you have no bowel movement by the third day, you may take a fiber supplement or milk of magnesia.


You may eat when you get home; however, be sure to consume only small portions of food until you rid yourself of the majority of the gas in your colon, as its presence may cause you to feel nauseated. Eating a full meal stretches the stomach and increases any bloated discomfort.


Nausea may be caused by the presence of gas, pain or effects of the procedure medication. This may last several hours. Your doctor should be notified if it persists into the following day. If your experience nausea, drink only clear liquids (any fluid you can see through), and do not eat solid food until the nausea subsides. Bed rest is recommended. If vomiting occurs, notify your physician.


The effects of Colyte, the prescription medicine used to clean the colon, and the frequent elimination that follows may cause hemorrhoids to be irritated to the point of bleeding. You may experience continued irritation for the next few days, until your rectal tissue has a chance to recover. You may use an over-the-counter preparation, such as Preparation-H or Anusol to ease any soreness. At no time should any present bleeding exceed the pre-procedure amount.

After the removal of polyps, you may notice a small streak of fresh blood on the toilet tissue or in the toilet bowl. This is not a matter for concern, as it may indicate only slight trauma to the wall of the bowel during the manipulation and passage of the colonoscope and is readily repaired by your body.

Notify Your Physician If You Experience Any Worrisome Symptoms

  • Fever, severe pain or excessive bleeding should be reported to your doctor immediately.
  • Localized irritation of the vein (phlebitis) at the I.V. site may occur at the site of medication injection and is not unusual. There may be a red streak going up your arm that is best treated with moist hot packs. If it progresses, contact our clinic, as antibiotic therapy may be required to resolve this condition.
  • Forgetfulness is normal immediately after the procedure and is due to the use of an amnesic drug required for adequate sedation during the procedure.
  • Should you have any questions after your procedure, please call our office and your call will be directed to your physician’s triage nurse. Phone: 541-868-9500 or Toll-Free: 877-484-4501

Your Test Results

A pathology report of any biopsied tissue should be received by our office in 14 days. If you have not heard from us after 14 days, please call our office and your call will be directed to your physician’s triage nurse.

It is your right to be thoroughly informed of the risks and possible complications before you decide whether or not to undergo the recommended colonoscopy procedure.

  • There is a 1 in 100 chance of some complication occurring when colonoscopy is used to diagnose your problem, but serious problems are very uncommon.
  • There is a 1 in 300 chance of a significant amount of bleeding from the colon or rectum. Minor bleeding is more common but seldom requires treatment. Any persistent bleeding should be reported to your physician.
  • There is a 1 in 500 chance of a puncture of the colon.
  • There is a risk of temporary irregularity of the heart rhythm. For this reason, if you have a history of heart disease, your heart may be monitored with an electrocardiogram to minimize risk to you.
  • There is a risk of an allergic reaction to the drugs administered during the procedure, although these are rare.
  • Death is extremely rare but remains a possibility.

Although any medical test has some risk associated with it, in actuality, serious problems with colonoscopy are very uncommon and when they occur, are very treatable. Because of its acceptability, low risk, accuracy and the wide variety of tasks it can accomplish, colonoscopy is well recognized as a very important test in appropriate situations and is used frequently in patients with lower bowel symptoms or problems.

Abdominal gas or bloating caused by the introduction of air into the colon to enhance and ensure good visualization. Walking assists the passing of gas. Refrain from eating large amounts of food until you have returned to your normal state of comfort.

Uncommonly, nausea may also be a result of the abdominal gas and/or the use of medications during the procedure. It is recommended that you remain on clear fluids until nausea subsides. Should vomiting occur over an extended period of time (more than 6 hours), please notify your physician. Bed rest is recommended.

Localized irritation of the vein (phlebitis) is rare but may occur at the site of medication injection. A tender lump develops which may remain for several weeks to several months, but goes away eventually. Elevation of the arm and hot, wet compresses applied to the site several times per day should rectify the situation. If a red streak should form which appears to follow the route of a vein or extends up your arm, please notify your doctor at once.

If any serious or persistent symptoms develop, you should notify your doctor.

The most common alternative to colonoscopy is barium enema. This examination requires barium (a chalky liquid) to be inserted into the rectum which fills the colon, after which x-rays are taken. Some abnormalities of the colon can be detected by studying these films. However, this procedure is generally recognized as not being as accurate as colonoscopy, nor does it allow for biopsy or removal of polyps.

Three procedures which may be done prior to colonoscopy (but are not considered alternatives to colonoscopy) are sigmoidoscopy, CAT scan and nuclear scan. Since findings from these three procedures may need to be confirmed by colonoscopy anyway, your physician may not perform them.

NOTE: The information provided here may not include additional information discussed or provided to you by your healthcare provider. It is not intended to serve as a complete description of a particular topic or as substitute for a clinic visit.