Medically reviewed by Onikepe Adegbola, MD, PhD
Colonoscopy is a medical test that examines the large intestine, colon, and rectum. The invasive technique requires a flexible tube called a colonoscope. It is inserted into the body through the anus and used to view polyps, bleeding, lesions, or any cancerous sign in the colon. Colonoscopy requires bowel prep. It is necessary to clean the whole colon to make it visible on the colonoscope; otherwise, the screening process would be difficult.
The prep for colonoscopy can be uncomfortable but is essential. It needs to be done correctly to avoid an additional colonoscopy. The doctors want to examine every part of the colon, and if it has any residual stool, it can make the visibility difficult. This article will discuss the bowel prep for colonoscopy.
Colonoscopy Prep: What To Expect
The goal of colonoscopy prep is to remove the food particles from the intestines completely. It includes special dietary instructions and preparation liquid that induces a kind of diarrhea, emptying the stools and waste. It ensures visibility during the procedure. A study suggested that colon prep should have little or no impact on the colon’s inner lining (mucosa) and cause minimum discomfort to the patient.
The bowel movements should be watery and clear. As per a research report, 25% of colonoscopies are canceled because of improper bowel preparations. It is, therefore, essential to have a successful bowel prep. The doctors cleanse the colon as per the guidelines issued by the American Gastroenterological Association, American College of Gastroenterology, and American Society for Gastrointestinal Endoscopy. Sometimes they change the guidelines as per the health of the individual, what they can tolerate and what has worked for them in the past.
Before the colonoscopy, doctors will prescribe several colonoscopy preps and ask for any ongoing medications such as blood thinners that can increase complications during the procedure. Here are some food choices and important instructions for the bowel preparation:
Food Choices Before The Colonoscopy
During the prep, the diet should be nutritious but should not form a large number of stools in the intestine. Emptying colon content is key to a successful procedure and requires the following instructions to be followed:
- Start a low-fiber diet a few days before the colonoscopy procedure as they are quick to digest and leave the body.
- It is advised to stop taking fibrous supplements three days prior to the procedure as they produce fecal matter that works against the bowel prep.
- Stop taking stool formers and iron and vitamin supplements five days before the appointment.
- You can have Jell-O, gelatin, popsicles, and flavored water.
- You have to stop eating nuts, raw vegetables, and seeds two hours prior to the procedure as they take a long time to digest.
- You have to be on a liquid diet on the day before the appointment, such as broth, tea, juice, and soft drink. You can add sugar to tea and coffee but avoid cream.
- It is advised to avoid anything with red or purple dye as they can change the colon color and interfere with the diagnosis.
Drinking Bowel-Cleaning Liquids
You have to drink the prep solution or medicines in the evening before the colonoscopy and in the morning, which will trigger bowel-clearing diarrhea. The dose is divided into two parts and called a split-dose regime. These prep solutions are laxatives that induce diarrhea. A study revealed that most cases use polyethylene glycol (PEG) and oral sodium phosphate (NaP) regimens to prep bowel.
You may feel nauseous after consuming the prep solution. As per Harvard Medical School health publishing, it is best to sip it slowly, take breaks between sips, or take medication to avoid nausea. If vomit occurs, it is advised to repeat the dose.
Once your prep starts, it is advised to take care of the following things:
- Make sure you are at home as you need to use the toilet many times
- Find someone to take care of your pets, belongings, children
- Pile up the toiletries and necessities
- Wear soft, loose, and comfortable clothing
- Check the prep instructions, timings, and doses.
- Drink plenty of liquid before, during, and after bowel prep.
- If the large intestine is difficult to empty, you may be asked to get an enema before the procedure.
How Long Diarrhea Will Last?
Bowel preparation involves two to three bowel movements. Once you take the liquid solution or prep, you start experiencing bowel movements within 30 minutes to one hour. The initial consistency of the stools will be a firm, semi-firm, or loose brown stool. Soon, you will experience high-volume and high-velocity diarrhea after taking the prep solution. When the bowel movement becomes clear and watery, the prep is done. Although the time taken to reach this point varies in individuals depending upon the gut health and prep diet plan, it usually takes 12 to 16 hours to completely prep the bowel for colonoscopy.
In some people, diarrhea can continue for a short period of time after the colonoscopy. It is due to a person’s food choice in the immediate periods just after the procedure. It is recommended to avoid fried food and opt for a solid, healthy, and nutritious diet.
You may need Vaseline or Desitin to soothe the skin surrounding the anus. You may experience some uncomfortable side effects of the prep, such as stomach cramping and gas. It is completely normal. But if you find blood or clots passed during the colonoscopy prep, seek urgent medical attention.
Colonoscopy preparations can be uncomfortable, time-consuming, and challenging but essential for proper examination of the colon and rectum. The instructions for the colonoscopy prep depend on the doctor, the time of colonoscopy, and any prior experience you have with the prep. Make sure that you follow proper dietary and prep instructions.
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