What is a colonoscopy?
A colonoscopy is an outpatient procedure that is done to examine the inside of your large intestine (colon and rectum). The examination uses an instrument called a colonoscope (sometimes called a scope). This flexible instrument is very long and includes a camera and the ability to remove tissue (you won't feel the tissue being removed). A colonoscopy is commonly used to evaluate gastrointestinal symptoms, such as bleeding, abdominal pain or changes in bowel habits (how often you poop, how easily you poop, and the color and consistency of your poop).
A colonoscopy can be used to detect many different types of conditions.
Some people may avoid the procedure due to embarrassment or a reluctance to go through the preparation. There are many bowel preparations available, and they come in different sizes and tastes. Also, the colonoscopy team respects your privacy during the entire procedure. Colonoscopies are done to check for colorectal polyps or cancer. Removing polyps early means they can’t turn into cancer.
The medical community recommends that anyone who does not have risk factors for colorectal cancer should begin regular colonoscopy screenings starting at age 45. The frequency of your colonoscopies will vary depending on the findings. You may need to have a colonoscopy at a younger age if you have a higher risk of colon cancer. Risk factors may include:
- Having familial polyposis syndrome (a condition that runs in your family and is linked to an increased risk of forming polyps).
- Having a genetic condition associated with colon cancer.
- Having inflammatory bowel disease, such as Crohn’s disease and ulcerative colitis.
- Having first-degree relatives with colon cancer (that is, your mother or father, brother or sister, or child).
- Having multiple relatives with colon cancer.
What should I know or tell my doctor before a colonoscopy?
Be sure to tell your doctor exactly what medicines you take on a daily basis. This includes prescription and over-the-counter products like supplements. Your doctor can tell you which medications to avoid and what changes might be necessary. It is possible that you might have to reschedule your medications if you have diabetes or need blood thinners.
You will need a driver. Most facilities will not let you check in or perform the exam at all if you do not bring a responsible driver with you.
To have a successful colonoscopy, you will have to do your part. This means following all the instructions about what to eat and drink in the days before the procedure. It also means making sure that your colon is empty so your doctor can see clearly when the scope is inside the colon. This involves what is known as ‘bowel preparation.’
Bowel preparation. Colonoscopy prep. Cleaning out your colon. What does this mean?
Your healthcare team will give you plenty of time to prepare. You will get instructions at least two weeks before the procedure. It is important to read and follow all of the instructions given to you. If your bowel is not empty, your colonoscopy will not be successful and may have to be repeated. The cleaner your colon, the better chance your provider will have at finding all of your polyps and cancer, which sometimes can be small or hidden.
What can you eat and drink in the days before a colonoscopy?
Some providers may ask you to avoid corn, nuts, seeds and popcorn for at least three days before the procedure. Others might suggest a low-fiber diet for two days before the colonoscopy. The day before the procedure you will not be able to eat solid food or drink alcohol
You will be able to drink clear liquids, including water, black coffee, tea, ginger ale, apple juice, white grape juice and clear broths. You can have JELL-O® and Popsicles®, but only those that are not red, blue or purple. Drinking extra fluid will help you not become severely dehydrated.
You should not drink or eat anything at all for at least four hours before the colonoscopy. Be sure to drink plenty of fluids the day before while you are doing your bowel prep. If you are having your colonoscopy with general anesthesia, then you cannot drink anything after midnight on the night preceding your test.
What exactly does bowel preparation mean?
There are a few different kinds of bowel preparations for colonoscopy, almost all of them liquid. Your doctor will tell you what kind is best for you based on your medical history and their particular preference. Some of these products are prescription-only, while others are available over-the-counter. They all have the same goal — to get rid of everything in your colon by causing watery diarrhea.
The time of day or night that you will have to start drinking the solution will depend on when your procedure is scheduled. You will be asked to consume the entire amount of liquid within a specific time period. There is also something called “split-dosing.” In split dosing, you will be asked to drink half of the bowel preparation the night before and then stop. You will get up in the morning and do the other half of the dose in the morning, finishing up at least four hours before the procedure itself. In general, split dosing results in cleaner bowel preparations. If you are having a colonoscopy with conscious sedation or twilight, and you have not been given split dosing instructions, ask your provider if you can do the split dosing.
What can you do to make a colonoscopy preparation easier?
There are things that might help you to drink the solution more easily. These include using a straw to drink the liquid and cooling the solution in the refrigerator before drinking it. You can add lemon drops or chew ginger candy. You will need to stay close to the bathroom during bowel preparation period. A split-dose might make the preparation easier. You will know you have done a good job when your diarrhea looks clear and yellowish, like urine.
You may experience skin irritation around the anus due to the passage of liquid stools. To prevent and treat skin irritation, you should:
- Apply Vaseline® or Desitin® ointment to the skin around the anus before drinking the bowel preparation medications. These products can be purchased at any drug store.
- Wipe the skin after each bowel movement with disposable wet wipes instead of toilet paper. These are found in the toilet paper area of the store.
- Sit in a bathtub filled with warm water for 10 to 15 minutes after you finish passing a stool. After soaking, blot the skin dry with a soft cloth. Then apply Vaseline or Desitin ointment to the anal area, and place a cotton ball just outside your anus to absorb leaking fluid.
What happens on the day of a colonoscopy?
Take a shower in the morning if you like, but do not use lotions, perfumes, or deodorants. Leave your jewelry, other valuables and contact lenses at home.
During the procedure itself:
- You are asked to wear a hospital gown and an IV will be started.
- The procedure can be done with conscious sedation, often referred to as “twilight,” or deeper sedation referred to as “general anesthesia.” You are given a pain reliever and a sedative intravenously (in your vein). You will feel relaxed and somewhat drowsy. This step means that the colonoscopy will not hurt.
- You will lie on your left side, with your knees drawn up towards your chest.
- A small amount of air is used to expand the colon so the doctor can see the colon walls.
- You may feel mild cramping during the procedure. Cramping can be reduced by taking slow, deep breaths.
- The colonoscope is slowly withdrawn while the lining of your bowel is carefully examined.
- The procedure lasts about 30 minutes. It takes about 12 minutes to move the scope five or six feet and another 12 minutes to take it out. If there are polyps to remove, the procedure will take longer.
What happens after a colonoscopy?
- You will stay in a recovery room for observation until you are ready for discharge. The amount of time that you are in recovery depends on whether or not you were sedated and what type of pain management medication you received.
- You may feel some cramping or a sensation of having gas, but this should pass quickly.
- Your responsible family member or friend will drive you home.
- Avoid alcohol, driving and operating machinery for 24 hours following the procedure.
- Unless otherwise instructed, you may immediately return to your normal diet. It’s recommended that you wait until the day after your procedure to resume normal activities.
- The doctor performing your colonoscopy will tell you when it’s safe to resume taking your blood thinners or any other medications you might have stopped.
- If polyps were removed or a biopsy was done, you may notice light rectal bleeding for one to two days after the procedure.
NOTE: If you have a large amount of rectal bleeding, high or persistent fevers, or severe abdominal pain within the next two weeks, go to your local emergency room and call the doctor who performed your exam.
How long will it be before my next bowel movement?
It might take a few days before you have a bowel movement because your colon is empty. It also depends on how much roughage (fibrous foods) you eat.
Care at Cleveland Clinic
- Schedule a Colonoscopy
- Find a Doctor and Specialists
- Make an Appointment
Results and Follow-Up
When will I know the results of the colonoscopy?
Usually, your doctor will speak with you after the procedure to explain what was done. The doctor will tell you if you did have polyps and if any tissue was removed. They will also go over when you are able to start taking your medications again if you had to stop taking something before the colonoscopy.
Also, usually you will get a formal report either mailed to you or sent to you and your primary care provider in your electronic medical record. Your healthcare team will let you know if any follow-up is needed based on the results of your colonoscopy.
Are there alternatives to colonoscopies?
There are other ways to screen for colon cancer. These include:
- Stool tests, such as the fecal immunochemical test (FIT), fecal occult blood test (FOBT), stool DNA tests (like Cologuard®). These tests let you collect your stool samples at home and then return them to your healthcare provider or mail them to a lab. You will have to do these more often than a colonoscopy.
- CT colonoscopy (also called a virtual colonoscopy).
- Flexible sigmoidoscopy, a test similar to the colonoscopy but covering a smaller part of the colon and the anus. It does not visualize the first part of the colon.
You and your healthcare provider should discuss the type of colon cancer screening that you should have. The choice will be based on your overall risk of colon cancer, general health, any symptoms you might be having and your personal preference. You should contact your health insurer about the costs of these less conventional tests.
You should know that some of the options that are not actual colonoscopies still call for the same type of preparation (cleaning out the colon by causing diarrhea). If polyps or other abnormalities are found on the alternative testing, they cannot be removed or treated. So it is likely that you will still have to have a colonoscopy. In addition, the costs of a screening colonoscopy may be less than of a colonoscopy completed after another, positive screening test other than colonoscopy.
Can you swallow a camera in a pill to take pictures of your colon?
Currently, the pill camera test is used to view the small intestine because the small intestine is easier to clean (for visibility) (the part of your bowel between your stomach and colon). Also, the camera passes through the small intestine in two to three hours.
The pill camera is being studied for colonoscopy. There are issues, though:
- The large intestine (colon) is wide and has folds and creases.
- It can take as long as 36 hours to pass the pill camera through the colon.
- The colon is not as easy to get and keep as clean as the small intestine.
Can you have a colonoscopy while you have your period?
The answer to this question is yes. You might want to wear a tampon if you have your period.
Can you have colonoscopy when you are pregnant?
A pregnant woman should always consult her obstetrician before having any kind of procedure. If you are having a colonoscopy for screening, it is best to wait after pregnancy. However, colonoscopy is generally believed to be safe during pregnancy.
What are the recommendations for scheduling your first and later colonoscopies?
If you are a person of average risk for colorectal cancer, the recommendation is to get your first screening test at 45. This might be a colonoscopy or a stool test. If your risk is higher or you have certain symptoms, your healthcare provider might suggest a colonoscopy or other screening test earlier than age 45. The incidence of colorectal cancer in African Americans has been increasing, and survival rates in those with colon cancer are worse than those for other groups.
You should discuss when to start screening with your healthcare provider. There are other sets of guidelines. For instance, the American Cancer Society suggests that screening for average risk people and African Americans start at age 45.
Follow-up colonoscopies will depend on the results of the first one. If you have no polyps and low risk, you might be able to wait 10 years before having another one. If you do have polyps and are considered high-risk, you might have to have a yearly procedure. (A colonoscopy every 10 years is the general rule for people who are not at high risk.)
Regular screening should be done through the age of 75. After that, you and your healthcare provider can decide on further screening needs.
Can a colonoscopy find parasites?
In the case of some parasites, like whipworms, the answer is yes. However, a colonoscopy is not the usual way to diagnose parasites.
Can a colonoscopy be used to diagnose endometriosis?
If you are a woman with endometriosis, you may have symptoms that affect your bowel, such as pain or bouts of constipation mixed with diarrhea. Your gynecologist might suggest a colonoscopy to rule out bowel problems. Usually, the endometrial tissue does not protrude through the bowel so it cannot be seen on a colonoscopy. Such tissue often sticks to the outside of the bowel or to other tissue in the area.
Can a colonoscopy be used to diagnose prostate cancer?
No. A colonoscopy is not designed to find prostate cancer. However, some doctors may choose to perform a digital rectal examination and a prostate examination before inserting the colonoscope. Men may believe that that their prostates have been examined, but this might not be true. It is a good topic to bring up with your doctor before a colonoscopy.
Here is a final thought about colonoscopies. Many people avoid them because they find the idea embarrassing and the preparation to be unpleasant. However, people often ask themselves and their care providers how we can prevent something from happening. Here is one way: colonoscopies can stop colon cancer before it starts.
Cleveland Clinic's Bowel Preparation Instructions
- Golytely, Nulytely, Trilyte or Colyte.
Follow a special diet the day before the exam.
Typically, you won't be able to eat solid food the day before the exam. Drinks may be limited to clear liquids — plain water, tea and coffee without milk or cream, broth, and carbonated beverages. Avoid red liquids, which can be mistaken for blood during the colonoscopy.
For the procedure, you'll lie on a table while the doctor inserts a colonoscope through your anus and into your rectum and colon. The scope inflates your large intestine with air for a better view. The camera sends a video image to a monitor, allowing the doctor to examine your large intestine.How many hours the procedure of colonoscopy? ›
A colonoscopy procedure typically takes 30-60 minutes, depending on whether the doctor needs to remove polyps or take biopsies. However, patients and caregivers should plan to spend 2-3 hours total at the hospital or endoscopy center to account for the time needed for preparation and recovery.What can I expect at my colonoscopy screening? ›
The colonoscopy will take between 20 and 60 minutes. Once you are sedated, you will lie on your side, and your doctor will insert a scope into your rectum. This scope is a thin tube with a tiny video camera at the tip that allows your doctor to see inside your rectum and colon to look for polyps or other abnormalities.How do I prepare for a colonoscopy in 2022? ›
Try eating lighter in the days leading up to the procedure. Avoid high-residue foods such as nuts, corn, peas and seeds at least three days before your exam. The day before your procedure, you can only have clear liquids such as water, tea, black coffee, apple juice and broth. You may also eat popsicles and gelatin.What foods are allowed 3 days before a colonoscopy? ›
OK to eat:
- Breads and grains made with refined white flour (including rolls, muffins, bagels, pasta)
- White rice.
- Plain crackers, such as Saltines.
- Low-fiber cereal (including puffed rice, cream of wheat, corn flakes)
During the procedure itself, your colonoscopy will not be painful at all. Most patients cannot even feel the tube when it is inside of them, and there is no pain during the post-procedure process. There are a few side effects that may occur after the procedure, which include: Distention.Is colonoscopy a difficult procedure? ›
An estimated 10 to 20 percent of colonoscopies are considered difficult. 80 percent of these are due to looping as a result of a torturous or redundant colon, and 20 percent can be attributed to a fixated / angulated sigmoid colon and / or strictures.Is colonoscopy a simple procedure? ›
“Colon and rectal cancer can be identified before it's too late, by doing colonoscopies. It's a simple procedure we can do to remove polyps so they never get the chance to turn into cancer.”How long do you go to the bathroom after colonoscopy? ›
It could take 2 to 3 days before you have a bowel movement after your colonoscopy because you completely emptied your colon and rectum ahead of the procedure.
Day of the colonoscopy
If your procedure is in the morning, you may need to get up earlier than usual to finish drinking the laxative. Drink the rest of the laxative 4 to 5 hours before you leave home for the procedure. Drink about an 8 ounce glass every 10 to 15 minutes, the same as the previous evening.
After the test, you may be bloated or have gas pains. You may need to pass gas. If a biopsy was done or a polyp was removed, you may have streaks of blood in your stool (feces) for a few days. Problems such as heavy rectal bleeding may not occur until several weeks after the test.How long does it take to wake up after colonoscopy? ›
What should I expect in recovery? Even under deep sedation, you will not remain asleep for long: That effect usually wears off within 30 minutes of the removal of the IV. You may feel bloated or pass gas for a few hours after the exam, but walking could help relieve the discomfort.Can I go to work the day after a colonoscopy? ›
Colonoscopy recovery is usually quick with most people resuming normal activity the next day. Even so, it is important not to rush back to work. It is best to take the remainder of the day to rest, recover from sedation, and replenish fluids and nutrition. The results of your exam should be available within a few days.What is the difference between a colonoscopy and a screening? ›
A “screening” colonoscopy is a colonoscopy that is done for the prevention of colorectal cancer and is considered a preventive health service. A screening colonoscopy will have no out-of-pocket costs for patients (such as co-pays or deductibles).What is the most common prep for colonoscopy? ›
Prep solutions used vary from surgeon to surgeon and can include Suprep in liquid form and Sutab in pill form, as well as over-the-counter options such as Miralax and Dulcolax mixed with clear fluids.Is it better to do a colonoscopy in the morning or afternoon? ›
Colonoscopies performed in the afternoon (PM) have been shown to have lower adenoma detection rates (ADR) compared to those in the morning (AM). Endoscopist fatigue has been suggested as a possible reason. Colonoscopies tend to be technically more challenging in female patients.Are you up all night before a colonoscopy? ›
The good news is that there is usually very little discomfort. You will likely be able to sleep through the night once the first round of evening prep is over. Finding colon polyps early before they can become cancerous can save your life and doing the prep is worth it.Are bananas OK before colonoscopy? ›
Three days before your colonoscopy eat low fiber foods:
Soft fruits, like bananas. Well-cooked vegetables without skin. Fruit without skin or seeds. Lean meat, chicken, or fish.
1 Day Before Your Colonoscopy (Prep Day)
Examples of a light breakfast are: eggs, soup or broth with noodles (no meat or vegetables), white crackers, white rice, white potatoes, white bread, Boost® or Ensure®. At 10:00 am, begin a clear liquid diet. Do not eat anything solid. No red, orange or purple products.
Two Days Before Your Appointment
Drink at least eight glasses of water today. STOP eating high-fiber foods such as vegetables and beans until after your colonoscopy. You can eat all other types of foods today. Drink the bottle of magnesium citrate after dinner.
Propofol works quickly; most patients are unconscious within five minutes. "When the procedure is over and we stop the intravenous drip, it generally takes only 10 to 15 minutes before he or she is fairly wide awake again.”Is a colonoscopy with a finger? ›
Your doctor might insert a gloved finger into the rectum to examine it before putting in the colonoscope. The colonoscope is lubricated with gel so it can be inserted easily into the rectum. It is then passed all the way up to the beginning of the colon, called the cecum.How deep does a colonoscopy go? ›
A colonoscopy allows an examination of the entire colon (1,200–1,500 mm in length).How painful is a colonoscopy afterwards? ›
A small percentage of people may experience mild abdominal cramping, similar to gas pains, after a colonoscopy. This may last for about a day after the procedure. The reason for this is because the doctor might have used a small amount of air to open up the colon to get a better view during the procedure.What kind of anesthesia is used for colonoscopy? ›
Most often, either moderate sedation or deep sedation with the anesthetic propofol are used for colonoscopies. An anesthesiologist is sometimes present for moderate sedation — sometimes called conscious sedation by patients, though the term is technically incorrect.Can a colonoscopy be done without anesthesia? ›
For most patients, a sedative is given in intravenous form to help relax and minimize any discomfort during the procedure. But did you know that using a sedative is optional? In many countries, sedation-free colonoscopies are the norm. Patients are alert and engaged during the procedure.How big is a colonoscopy camera? ›
The length of the scope is roughly 160 cm - 180 cm with, a diameter of about 1.0 cm to 1.2 cm, depending on the manufacturer and scope size. At the end of the colonoscope, there are several vital working parts.What is the main cause of colon polyps? ›
Mutations in certain genes can cause cells to continue dividing even when new cells aren't needed. In the colon and rectum, this unregulated growth can cause polyps to form. Polyps can develop anywhere in your large intestine.What position do you lie in for a colonoscopy? ›
You'll lie on your left side on an exam table, and you'll likely fall asleep. The doctor will insert the colonoscope into your rectum and pump air into the colon to get a better view of your colon's lining. The doctor will be able to see changes such as polyps, masses, inflammation or hemorrhoids.
- spicy or well-seasoned foods.
- whole or chopped nuts.
- fried foods, such as chicken fingers and french fries.
- raw or undercooked vegetables.
If you cannot get the urine flowing properly after six hours, contact the nurses or your doctor. You may need a catheter (fine plastic drain tube) put in your front passage to drain the urine from your bladder until you are able to pass urine comfortably on your own.What is the most common complication after colonoscopy? ›
Bleeding is one of the most common complications of colonoscopy, accounting for 0.3-6.1% of cases[35,36].Can I take a shower before colonoscopy? ›
What happens on the day of a colonoscopy? Take a shower in the morning if you like, but do not use lotions, perfumes, or deodorants. Leave your jewelry, other valuables and contact lenses at home.Do you need to stay home the day before a colonoscopy? ›
The day before your colonoscopy, you can go to work as usual if you work regular business hours. One interruption in your daily life is that you are instructed not to eat solid foods. You will need to stay on a clear liquid diet all day. This diet includes water, black coffee, Gatorade, Jell-O, clear broth, and juice.How long does diarrhea last after colonoscopy? ›
You may experience loose stool or no stool for up to three days following the procedure.What are two potential problems after a colonoscopy? ›
Complications related to colonoscopy include, but are not limited to, the following: Continued bleeding after biopsy (tissue sample) or polyp removal. Nausea, vomiting, bloating or rectal irritation caused by the procedure or by the preparatory bowel cleansing.Can you be left alone after a colonoscopy? ›
Medicines you were given can change the way you think and make it harder to remember for the rest of the day. As a result, it is NOT safe for you to drive a car or find your own way home. You will not be allowed to leave alone. You will need a friend or family member to take you home.
The First 24 Hours of Recovery
Because a colonoscopy is performed with the patient under the effects of sedation, the patient will need to arrange for a ride home. Once they are at home, patients should allow themselves at least 24 hours to rest and recover.
Don't drive or make important decisions or go back to work for the rest of the day. You may feel bloated or pass gas for a few hours after the exam, as you clear the air from your colon. Walking may help relieve any discomfort. You may also notice a small amount of blood with your first bowel movement after the exam.
A gastroenterologist, the specialist who usually performs a colonoscopy, can't tell for certain if a colon polyp is precancerous or cancerous until it's removed and examined under a microscope.Who needs colonoscopy screening? ›
Regular screening, beginning at age 45, is the key to preventing colorectal cancer and finding it early. The U.S. Preventive Services Task Force (Task Force) recommends that adults age 45 to 75 be screened for colorectal cancer. The Task Force recommends that adults age 76 to 85 talk to their doctor about screening.What is considered high risk for screening colonoscopy? ›
For people at increased or high risk
A strong family history of colorectal cancer or certain types of polyps (see Colorectal Cancer Risk Factors) A personal history of colorectal cancer or certain types of polyps. A personal history of inflammatory bowel disease (ulcerative colitis or Crohn's disease)
(KOH-luh-NOS-koh-pee) Examination of the inside of the colon using a colonoscope, inserted into the rectum. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease.Do and don'ts before colonoscopy? ›
Remember, you can't drink anything for at least 2 hours before your procedure. You must have someone to take you home after your colonoscopy and stay with you for at least two hours. Do not use alcohol, marijuana, or other substances that could impair your thought process prior to your appointment.What should you avoid a week before a colonoscopy? ›
- Avoid nuts, seeds, dried fruits, dried beans and peas.
- Avoid whole grains and cereals.
- Choose cooked or canned fruits and vegetables over fresh ones.
- Choose white bread, white rice and products made with refined flour.
- Drink juices without pulp.
The day before the colonoscopy procedure — Don't eat solid foods. Instead, consume only clear liquids like clear broth or bouillon, black coffee or tea, clear juice (apple, white grape), clear soft drinks or sports drinks, Jell-O, popsicles, etc.Do you have to drink all 4 liters of colonoscopy prep? ›
Yes. You must drink all the prep to fully clean out your colon for a safe and complete colonoscopy. I feel like throwing up (nausea) or did throw up (vomit) after taking the bowel prep.What can I have 2 days before a colonoscopy? ›
- Well cooked, lean (low fat) beef, lamb, ham, veal or pork.
- Fish, shellfish or poultry.
- White rice, noodles or white pasta.
- Cereal including cornflakes and crisped rice cereal, but not bran.
- White bread or toast.
- Rich tea or other plain biscuits.
- Eggs, especially boiled or poached.
The night before your colonoscopy you'll take strong laxatives to clear your digestive tract. The method recommended for most people is called split dosing. You'll drink a half-gallon of liquid laxative in the evening. Then you'll get up about 6 hours before your appointment to drink another half-gallon.
SUTAB includes 24 tablets that must be taken before the colonoscopy. You must split it up into two doses of 12 tablets each. You start by taking 12 tablets the evening before the colonoscopy. The morning of the colonoscopy, you must complete the second dose of 12 tablets.How long before a colonoscopy should I stop drinking water? ›
Beginning four hours before your procedure, you should STOP drinking clear liquids. This means that you should not have anything to eat or drink beginning four hours before your procedure. After your procedure, you will be able to resume a normal diet, unless otherwise instructed by your doctor.Is colonoscopy done empty stomach? ›
New research suggests that the grueling process of preparing for a colonoscopy may not have to be endured on an empty stomach. Colonoscopy patients typically have to forgo all solid foods and go on a clear-liquid diet while taking laxatives the day before their procedure.What if I am still pooping before colonoscopy? ›
14. What if I am still passing stool the morning of my test? Take a tap water enema until you run clear. If this does not work, call the office.How many hours will I poop after colonoscopy prep? ›
Most of the time, people begin to have bowel movements about 3 hours after drinking the solution, so if a person has not experienced bowel movements by this time, the prep may not be working.