What can I eat 2 days before a colonoscopy?

What to Eat 2 Days Before a Colonoscopy

You can eat a normal, unrestricted diet two days before your colonoscopy—dietary modifications should only begin the day before the procedure. 1, 2

Dietary Timeline

Two Days Before (72 Hours Prior)

• No dietary restrictions are necessary for patients at low risk for inadequate bowel preparation 1, 2
• You may consume your regular diet, including foods with fiber 1, 2
• Research confirms that foods consumed 2-3 days before colonoscopy show no association with bowel preparation quality 3
• Additional days of dietary restrictions beyond one day before colonoscopy provide no benefit in bowel preparation adequacy 1, 2

One Day Before (24 Hours Prior)

• Switch to a low-residue/low-fiber diet for early and midday meals 1, 2
• Avoid high-fiber foods including cereals, beans, peas, nuts, seeds, and raw or dried fruits and vegetables 1, 2
• Transition to clear liquids for the evening meal and continue until the procedure 2
• Research suggests avoiding red meat, poultry, and vegetables on this day, while gelatin consumption may be beneficial 3

Important Medication Consideration

Discontinue iron supplements at least 7 days before your colonoscopy (not just 2 days before) 1, 4

• Iron causes dark, sticky stool that adheres to the colonic mucosa and obscures detection of polyps and lesions 4
• This applies to all oral iron formulations including ferrous sulfate, ferrous gluconate, and ferrous fumarate 4

Special Populations at Higher Risk

If you have any of the following conditions, you may need more restrictive dietary preparation starting 3 days before (not 2 days):

• Prior inadequate bowel preparation 2
• History of constipation (OR 1.3) 1
• Diabetes mellitus (OR 1.8) 1
• Parkinson disease (OR 3.2) 1
• Cirrhosis (OR 3.4) 1
• Dementia (OR 3.0) 1

For these high-risk patients, consider clear liquids only starting the day before colonoscopy rather than a low-fiber diet 2

Evidence Quality and Rationale

The recommendation to limit dietary restrictions to one day before colonoscopy is based on high-quality guideline evidence from the American Gastroenterological Association 1, 2. This approach is supported by research showing that:

• Only 17% of patients complied with diet restrictions 2 days before colonoscopy, while 77% complied 1 day before 3
• A 3-day low-fiber diet provides no benefit over a 1-day diet and is harder to perform 5
• Patients find 1-day diet restriction more tolerable and easier to comply with compared to longer durations 1

Common Pitfall to Avoid

Do not unnecessarily restrict your diet for more than one day before colonoscopy—this reduces compliance without improving outcomes and makes the preparation more burdensome 2