Introduction
One of the functions of our colon is to store poop before it exits our body. Therefore, before a colonoscopy, the colon has to be thoroughly emptied and completely clean. The process of doing this is called bowel preparation.
Bowel preparation is arguably the most important part of the colonoscopy journey. If your bowel (colon) is not clear:
- Abnormalities such as polyps or small tumours can be missed
- Risk of complications of colonoscopy increases
- High likelihood that the colonoscopy has to be repeated a few weeks later
How is bowel preparation done?
There are actually 2 parts to bowel preparation:
- Restricting your diet one day before the colonoscopy
- Drinking a strong laxative
Restricting your diet one day before colonoscopy
One day before your colonoscopy, you can eat:
- White rice
- White bread
- White noodles
- Skinless chicken
- Steamed fish
- Clear chicken broth
- Black Coffee or tea without milk (sugar is allowed)
- Plain water
- Clear fruit juice (without pulp)
In general, fibre is very good for our digestive system, but because it has a tendency to stick to our colon, please avoid it one day before the colonoscopy.
Do not eat:
- Oats
- Cereal
- Nuts
- Fruits
- Vegetables
- Red meat
- Dairy products such as milk, yoghurt
If you are taking iron tablets, please stop iron tablets 3 days before the colonoscopy.
After you have completed your colonoscopy, please resume eating fruits and vegetables as they are good for your health.
Drinking a strong laxative
The laxative that I prefer my patients to drink is a medication called Fortrans. It is the safest laxative, and also the one that results in the cleanest bowel preparation.
Fortrans comes in the form of a sachet, and you will be provided with 3 sachets. Each sachet needs to be diluted in 1 litre of water. Once you have made the mixture, please divide the 1 litre mixture into 4 cups of 250 mls each, and drink each cup every 15 minutes (hence, finish 1 litre within an hour). In total, you will drink 3 litres of the Fortrans mixture. You will drink 2 litres one day before the colonoscopy, and 1 litre on the day of colonoscopy (please see the recommended schedule below).
I strongly recommend my patients to drink Fortrans at home, but it can be prepared by our nurses at Daycare if you are not confident of preparing the mixture and drinking it at home. The main advantage of drinking it at home, is that we can do your colonoscopy as early as 8am as you would have arrived at the hospital completely prepared. The other advantage is, you will be in the comfort of your own home when you need to go to the toilet to empty out your colon.
Patients who drink Fortrans at Daycare usually are only ready for their colonoscopy at around 11am or 12 noon.
Recommended schedule
1 day before your colonoscopy
All throughout this day, please remember to restrict your intake to certain foods as outlined previously.
8 am – Have your breakfast
12 noon – Have your lunch
4 pm – Have an early dinner. After this, no more food is allowed, but please drink plenty of water.
6 pm – Drink 1 litre of Fortrans
8 pm – Drink 1 litre of Fortrans
10 pm – Go to sleep
Day of colonoscopy
When you wake up, it is now the day of your colonoscopy. Please do wake up early to finish your 3rd and final litre of Fortrans.
5 am – Drink 1 litre of Fortrans
730 am – Arrive at hospital
8 am onwards – We can start your colonoscopy
Please remember
Drinking Fortrans alone will not result in a clean colon if strict adherence to dietary restriction is not followed.
For us to know if your colon is adequately clean for the colonoscopy, you must achieve 2 parameters:
- Only pure water comes out when you do a poop (no solid material is seen)
- The colour of the water is light green or orange or yellow (like the colour of urine). If the colour of water is brown, you are not quite ready yet for your colonoscopy.
If you do not achieve these 2 parameters, please let us know once you arrive to Daycare. We may ask you to drink another litre of Fortrans. To make it easy for our nurses, please snap a photo of your last bowel movement after finishing drinking 3 litres of Fortrans.
Lastly, in a small minority of patients, Fortrans can cause severe nausea. To reduce this, here are some tips and tricks:
- Prepare the 1 litre Fortrans solution ahead of time, and chill it in the fridge so that it is cold by the time you drink it. Drinking the Fortrans mixture at room temperature can result in nausea for some patients.
- Drink it using a straw.
- Squeeze some lemon juice into the mixture so that it imparts a nice flavour.
