How to prepare for a colonoscopy?

At the pharmacy, we often see patients looking for the medications to prepare for a colonoscopy. We can help by selecting the right medications for you and clarifying the dosing instructions to get you ready for the procedure.

In Ontario, Colorectal cancer screening is recommended for people 50 years and older. For most people, a simple at home test called the Fecal Occult Blood Test (FOBT) can be done every 2 years. However, for people at increased risk because of a family member with a diagnosis of colorectal cancer, a colonoscopy is recommended.  A colonoscopy can also be recommended as a follow-up test for an abnormal FOBT result.

It is important to do the colonoscopy because if colon cancer is caught early, it has a 90% chance of being cured.  It is a procedure that is done at the hospital, where a doctor will examine the colon, take biopsies and remove any abnormal growths. The procedure lasts about half an hour and you can receive a sedative medication on site to make you more comfortable during the procedure.

Preparing for a colonoscopy:

To prepare for a colonoscopy, patients will likely receive an instruction sheet that explains what they have to do during the 2 days prior to the procedure date. If you have not received any information, be sure to contact the clinic for the details because your clinic or your doctor may have their own specific recommendations for the preparation of a colonoscopy.

In general, you will be asked to empty your colon because any residue in your colon may obscure the view during the procedure. You will be instructed to follow a special diet the day before the exam. Usually, you will not be allowed to eat solid food the day before the procedure. Clear liquids such as plain water, tea or clear broth are generally allowed, however, you may not be able to eat or drink anything after midnight before the procedure.

You will also be instructed to take laxatives, so it is recommended that you stay home during the day prior to the procedure since you will be using the bathroom frequently.

The medications used for colonoscopy preparation can be purchase without a prescription, however, for patients 65 years and older, the Ontario drug benefit (ODB) will cover the cost of these medications with a prescription from your doctor. If you do not have a prescription yet, we can ask your doctor to send us a prescription.

In general, you will be instructed to take an oral tablet laxative (Dulcolax or Bisacodyl) 2 tablets at bedtime, 2 days before the procedure. And then on the day before the procedure, you will be asked to use a powder sachet laxative (Pico-Salax or Purg Odan) 2 times during the day, about 4 hours apart.

The timing for taking the powder sachet laxative depends on the time of the procedure scheduled on the next day. For instance, if the procedure is scheduled for the morning, then both packets of powder sachets are used on the day BEFORE the procedure.

However, if the procedure is scheduled for the afternoon, you may be asked to use one packet of the powder sachet laxative on the day before the procedure and one packet on the morning of the procedure date.

The time that you have to take these medications is usually specified in the instruction sheet, it is very important for you to follow the given instructions.

The powder sachet laxative has to be mixed in water prior to taking it. It is recommended to mix the powder in 5 oz (150ml) of cold water and stir it frequently prior to drinking it. Do not use hot water
to mix the powder because the mixture will get very hot and difficult to drink.

Be sure to tell your doctor about the medications that you are currently taking, especially if taking supplements that contains iron or medications that thins your blood (i.e. Aspirin, Plavix, Coumadin - warfarin, Pradax, Xarelto, etc.).

At Custom Care Pharmacy, we can prepare a medication profile report for you to bring to your doctor so that they can see a complete list of medications that you are currently taking. 

The doctor may need to adjust your dosage or stop certain medications temporarily to avoid any problems during the colonoscopy. If you have any questions about the medications that you need to purchase for your upcoming colonoscopy, please feel free to contact us at Custom Care Pharmacy 905-305-0111