If you're scheduled to have a colonoscopy, then your doctor may have mentioned that you'll need to go on a special diet for a few days before the test. Why do you need to do this and what changes will you need to make?
Why Watch What You Eat Before a Colonoscopy?
A successful colonoscopy relies on you having clear and empty bowels. The instruments used in the test need to have an unimpeded view of the colon so that they can spot problems if there are any.
While you're likely to be told to take laxatives or to use an enema to clear your bowels shortly before the procedure, this may not be enough to completely empty you out. So, you'll typically be told to switch to a special diet a few days before the test. You may also get different instructions on what you can eat the day before.
If you stick to these instructions, your bowels will be in the best condition for the test. The food you eat on your temporary diet moves through your system more easily and quickly. This ensures that nothing is missed during the investigation because your bowels are partly full.
What Should You Eat Before a Colonoscopy?
If you're told to switch to a modified diet a few days before a colonoscopy, then you usually cut high-fibre foods out of your diet. You switch to eating food that is lower in fibre for a few days. The aim here is to eat things that can be digested quickly and that don't stay in your system for very long.
For example, you may have to eat white bread instead of brown; you may be asked to switch to soft, lean meats like chicken rather than eating tougher, fatty meat like beef. While you may be able to eat fruit and vegetables, you may be told to take the skin off these foods and to avoid eating their seeds. Skin and seeds are less digestible and may remain in your bowels where they can impede visibility.
In some cases, you may be told to stop eating solid foods the day before the colonoscopy. If you're told to do this, then you should usually stick to eating and drinking clear fluids like broths. You can still have a cuppa, but you should cut out the milk at this stage.
Your gastroenterology clinic or department can tell you exactly what you need to do before your colonoscopy. They should give you a list of specific instructions. If you aren't sure what you can or can't eat at that point, call them for advice.