What is a colonoscopy?
A colonoscopy is an endoscopic procedure where a long, thin, flexible tube or “scope” is placed into the rectum and advanced through the entire colon (large intestine). The scope has a light and a camera on the end of it which allows the physician to examine the lining of the colon. A colonoscopy may be performed to diagnose the cause of gastrointestinal symptoms such as diarrhea, bleeding, abdominal pain, or abnormal x-ray results. A colonoscopy may also be performed on an asymptomatic patient at age 50, or sooner depending on the patient’s history, to screen for colon cancer and polyps
WHAT SHOULD I EXPECT THE DAY BEFORE THE PROCEDURE?
You will receive instructions from your doctor regarding the necessary bowel preparation to get you ready for your exam . Most patients will be on clear liquids the entire day before the exam. There are several different options for laxatives to entirely clean out the colon. It is very important to follow the instructions given to you by your doctor. There will also be additional instructions regarding your medications. In most cases, your medications will be continued as usual. However, in certain circumstances, especially in patients on blood thinners (i.e. coumadin, warfarin, plavix, aspirin, antiinflammatories) and in diabetics, special instructions will be given. Patients will be instructed not to take anything by mouth after midnight except for medications.
WHAT HAPPENS ON THE DAY OF THE PROCEDURE?
You will be asked to arrive at the Endoscopy center 1 to 1.5 hours before your exam. This is to allow time to fill out paper work and prepare for the exam. You will be asked to change into a medical gown. An intravenous (IV) catheter will be started in your arm so that sedation can be administered. You will be connected to equipment which will allow the doctor and staff to monitor your heart rate, blood pressure, pulse, electrocardiogram, breathing and oxygen level during and after the exam.
Once in the exam room, you will be asked to lie on your left side on the stretcher. The IV sedation will be started. Small amounts are given at a time to assure that you do not have any reactions to the medication and to provide only the amount that you need individually. Once an adequate level of sedation is achieved, the physician will perform a rectal exam. The colonoscope will then be gently inserted into the rectum. The scope will be carefully advanced throughout the colon to where the small bowel and colon meet. A small amount of air is injected through the scope into the colon to help the physician see. Any fluid remaining in the colon after the preparation can be washed and suctioned out through the scope. Depending on the findings of the exam, several things can be done at the time of the procedure including biopsies, removal of polyps, and control of bleeding. At the end of the procedure, as much of the air and remaining fluid as possible is suctioned out of the colon through the scope. Depending on the findings, the exam takes approximately 15-30 minutes.
After the exam is complete, the patient is taken to the recovery room to be monitored while the sedation starts to wear off. The amount of sedation used during the exam and the patient’s individual response to the medication will dictate how quickly the patient wakes up, though most patients are awake enough for discharge within 45-60 minutes. You will not be allowed to drive for the rest of the day; therefore, you will need to arrange for a ride home. You will also be instructed not to work, sign important papers, or perform strenuous activities for the rest of the day. Most patients are able to eat and drink normally after their discharge from the Endoscopy unit, however, specific instructions regarding activity, eating, and medications will be given to the patient prior to discharge.
WHEN WILL I GET MY RESULTS?
After the exam, the doctor and/or nurse will go over the findings of the procedure with you. Most patients will not remember what they are told after the exam because of the effects of the sedation. It is recommended, if possible, to bring someone with you to whom the results can also be discussed. The patient will also go home with a typed report. The patient will be informed of any biopsy results usually within one week.
WHAT ARE THE RISKS OF THE EXAM?
In general, colonoscopy is a very safe procedure. Overall, complications occur in less than 1% of patients. Most complications are not life-threatening, however, if a complication occurs, it may require hospitalization and surgery. Prior to the exam, a consent form will be reviewed with the patient by the nursing staff. Should any questions or concerns arise, these can be discussed with your physician prior to beginning the procedure.
Medication reactions associated with the sedation can occur. These can include but are not limited to allergic reactions, difficulty breathing, affects on the heart and blood pressure, and irritation of the vein used to give the medication.
Bleeding can occur with biopsies and the removal of polyps. Again, significant bleeding which might require a blood transfusion or hospitalization is very uncommon. However, bleeding can occur at the time of the exam or out to 2 weeks after the exam if a polyp is removed.
Perforation or puncture of the colon can occur. This may be recognized at the time of the exam, or it may not be apparent until later in the day. In most cases, a perforation will require a surgery and hospitalization. This is an uncommon complication, even when polyps are removed.
It is very important that the patient contact the doctor’s office immediately if symptoms arise after the procedure such as worsening abdominal pain, bleeding, or fever.
Like any other test, a colonoscopy is not perfect. There is a small, accepted risk that abnormalities including polyps and cancers can be missed at the time of the exam. It is important to continue to follow-up with your doctors as instructed and inform them of any new or persistent symptoms.
WHAT ARE ALTERNATIVES TO A COLONOSCOPY?
To an extent, the alternatives to the exam will depend on the reason for needing to undergo the colonoscopy in the first place. In most cases, the colonoscopy is the best method to evaluate and treat abnormalities in the colon. However, there are different x-rays which can evaluate the colon including barium enema, virtual CT scan. These are however only diagnostic exams. Treatment of abnormalities will require a colonoscopy or surgery.