The Colonoscopy Prep: Why Laxatives Are Necessary

Preparing for a colonoscopy involves cleansing your bowels with a laxative formula. This is because the procedure requires your doctor to see inside your colon, and if your colon isn't clear, they won't be able to see properly. Laxatives can be taken as pills or liquid preparations, and they are usually taken the night before the procedure. It's important to follow the instructions for taking laxatives carefully, as inadequate preparation may mean your colonoscopy has to be rescheduled.

Why laxatives are necessary before a colonoscopy

Laxatives are necessary before a colonoscopy to empty the bowels, allowing doctors to clearly and thoroughly examine the colon. This is because the signs of colorectal cancer, such as polyps, are often small and cling to the inside walls of the colon. If the colon is not clear, the procedure may have to be rescheduled.

Laxatives are usually taken in the form of oral formulas, which can be bought over the counter or with a prescription. These formulas typically include osmotic laxatives, which trigger the bowels to draw in more water from the body, softening the stools and increasing the volume in the colon. This triggers muscle contractions that move everything out. Electrolytes are also included in these formulas to prevent dehydration and significant electrolyte deficiencies, which can have severe consequences.

The process of preparing for a colonoscopy can be inconvenient and unpleasant, but it is important to remind yourself that it is a smart step to protect your health. Preparing well will ensure that your colonoscopy is effective, and if your results are good, you may not need another one for 10 years.

How to take laxatives

To prepare for a colonoscopy, it is essential to cleanse your bowels using a laxative formula. This ensures that your doctor can see inside your colon clearly during the procedure. Here is a detailed guide on how to take laxatives for an effective bowel cleanse:

Step 1: Plan Your Prep

Speak to your doctor to determine the most suitable laxative formula for you. Some common options include polyethylene glycol (PEG) kits, oral sodium phosphate (OSP) kits, and saline-based laxatives. Your doctor will provide instructions on when and how to take the laxatives. It is important to read and follow these instructions carefully. Ask your doctor any questions you may have and clear your schedule for the day before and the day of the procedure.

Step 2: Adjust Your Diet

Several days before your colonoscopy, you should tweak your diet to facilitate the bowel cleansing process. Eat light, low-fiber foods that are easy to digest. Recommended foods include white bread, pasta, rice, well-cooked vegetables without skin, and fruit without skin or seeds. Avoid raw fruits and vegetables, whole grains, seeds, nuts, and corn. Stop taking vitamins, supplements, and certain medications as advised by your doctor.

Step 3: The Day Before Your Colonoscopy

On the day before your procedure, you should only consume clear liquids. This includes sports drinks, clear juices (like apple and white grape), broth, soda, coffee, and tea without cream. Ensure that the liquids are not red, purple, or orange, as these colors can interfere with the colonoscopy results. Drink at least one 8-ounce cup of liquid every hour while you are awake to stay hydrated. Stop consuming all liquids two to four hours before the procedure, as advised by your doctor.

Step 4: Taking the Laxatives

Follow your doctor's instructions for taking the laxatives. Typically, laxatives are taken in split doses, with one dose taken the evening before the colonoscopy and the other dose taken on the morning of the procedure. For example, with the MiraLAX® preparation, you would take bisacodyl tablets and mix the MiraLAX powder with a clear liquid. You then drink a specified amount of this mixture at regular intervals. Other laxative preparations, such as SUTAB and OsmoPrep, involve taking a certain number of tablets with sips of water at specific intervals. Always follow the timing and dosage instructions provided by your doctor or the laxative packaging.

Step 5: Managing Side Effects

The laxatives will stimulate frequent and forceful bowel movements, which may cause discomfort. To manage this, stay in the bathroom and bring items to entertain yourself, such as a book, television, or laptop. Apply diaper cream before the diarrhea starts, and use moist or medicated wipes for cleaning. If you experience nausea or vomiting, try mixing the laxative with flavored drinks, chilling the mixture, or taking breaks between drinking it.

What to eat and drink before a colonoscopy

Preparing for a colonoscopy involves cleaning out your bowels so your doctor can see inside your colon. This process usually begins a few days ahead of time and involves taking laxatives and making changes to your diet.

Three to Four Days Before

Eat light and low-fiber foods that are easy to digest and leave your system quickly. This includes:

• White bread, pasta, and rice
• Well-cooked vegetables without skin
• Fruit without skin or seeds
• Lean meat, chicken, or fish
• Sports drinks, juices, and broths

Two Days Before

For the two days leading up to your colonoscopy, eat a low-fiber diet and avoid the following:

• Seeds
• Nuts
• Corn
• Popcorn

One Day Before

On the day before your colonoscopy, only consume clear liquids and avoid solid food and red liquids. Drink lots of clear liquids to stay hydrated, such as:

• Sports drinks
• Clear juice (e.g. apple and white grape)
• Clear broth
• Soda
• Black coffee or tea without cream
• Gelatin and ice pops (avoid red, blue, or purple dyes)

Two to Four Hours Before

Stop consuming all liquids, including clear ones.

What to expect after taking laxatives

After taking laxatives, you will experience significant diarrhoea, which is a normal effect of the medication. Plan to stay near a bathroom as you will need to empty your bowels frequently and forcefully. Mild bloating and abdominal cramps are also common side effects. Drinking the laxative medication slowly over a longer period can help alleviate these symptoms.

The laxatives will trigger muscle contractions that move everything out of your colon. This process can be dehydrating, so it is important to stay hydrated by drinking plenty of clear fluids such as sports drinks, clear juices, and broth. Avoid red, blue, or purple drinks as these can discolour the lining of the colon and make it harder for the doctor to see during the colonoscopy. Alcohol should also be avoided as it can cause dehydration.

You may experience other side effects such as nausea and vomiting. If this occurs, contact your doctor, as they may recommend you take a short break from the laxatives. Staying in the bathroom and bringing entertainment, such as a book, television, or laptop, can help make the process more comfortable. Applying diaper cream before the diarrhoea starts and using moist or medicated wipes to clean yourself can also provide relief.

It is important to follow the instructions provided by your doctor for taking the laxatives and preparing for the colonoscopy. This includes making any necessary diet changes, such as eating light, low-fiber foods, and avoiding solid foods and red liquids the day before the procedure.

What to do if you feel sick after taking laxatives

Yes, it is standard procedure to take a laxative before a colonoscopy. This is to clear out your bowels so that your doctor can see inside your colon.

If you feel sick after taking laxatives, there are several things you can do to manage your discomfort:

• Stay hydrated: Drink plenty of clear liquids such as sports drinks, clear juices like apple or white grape juice, and clear broth. It is important to drink enough fluids, especially if you are experiencing diarrhoea, to prevent dehydration.
• Electrolyte balance: Diarrhoea can lead to an electrolyte imbalance. Include electrolytes in your fluids to help maintain a balance and prevent deficiencies.
• Manage nausea: If you are feeling nauseated, try sucking on a lemon slice or a piece of hard candy. You can also ask your doctor for recommendations on over-the-counter medications to help with nausea.
• Dietary adjustments: In the days leading up to your colonoscopy, eat light, low-fiber foods that are easy to digest. Avoid solid foods the day before your procedure and stick to clear liquids.
• Consult your doctor: If you are experiencing severe side effects such as vomiting, severe abdominal pain, weakness, or unusual tiredness, contact your doctor immediately. They may recommend adjustments to your laxative regimen or additional medications to help manage your symptoms.

Frequently asked questions