Dietary restrictions for colonoscopy in adults

On the day before colonoscopy, it is usual practice for the patient to stop eating solid foods and consume a large volume of clear fluids (3 L or more)Hassan, 2019. There is no evidence that a small amount of milk in tea or coffee decreases the effectiveness of bowel preparation; to avoid caffeine withdrawal, patients who normally drink tea or coffee can continue to do so. There is some evidence that a diet low in insoluble fibre is as effective as a clear fluid dietParra-Blanco, 2014, but it is not routinely recommended due to the potential for confusion about what constitutes a low-fibre diet. For an afternoon colonoscopy, the patient may eat a low-fibre breakfast the day before the procedure, followed by a large volume of clear fluids (3 L or more). Patients should avoid eating seeds for about a week before the colonoscopy.

No fluids should be consumed for at least 2 hours before anaesthesia. This period may need to be extended if the patient has suspected or known delayed gastric emptying (eg due to gastroparesis)—seek expert advice.