Dr. Elizabeth Squirell · Gastroenterologist · Kingston Health Sciences Centre
Getting ready for a colonoscopy
A step-by-step guide to bowel prep. A clean bowel means a better, safer test, and less chance you will need to do it again.
Key points
- Your clinic's instructions come first. Read them as soon as you get them, and call if anything is unclear.
- At least a week before, tell your clinic if you take blood thinners, diabetes medicines, GLP-1 medicines (like semaglutide or Ozempic) or iron pills. Do not stop anything unless they tell you to.
- Eat low-fibre foods the day before, then switch to clear fluids. Avoid anything red or purple.
- Take the prep in two parts: the first the evening before and the second the morning of your test, as your clinic tells you.
- Finish the prep on time. Stop drinking when your clinic tells you, often 2 hours before the test.
- You are ready when your stool is watery and clear or yellow, with no solid bits.
- If you get sedation, an adult must take you home. Do not drive for 24 hours.
Go to emergency or call 911 if you have
- Severe belly pain or a hard, swollen belly after the test
- A fever or chills after the test
- More than a small amount of blood from your bottom, or blood clots
- Vomiting, and you cannot keep fluids down
- Feeling faint, dizzy or very weak
- Chest pain or trouble breathing