Algorithm for selecting a bowel preparation before colonoscopy in adults

PEG-ELS: polyethylene glycol-electrolyte solution.
* Patients who are at risk of electrolyte abnormalities include patients with a history of congestive heart failure, renal insufficiency, end stage liver disease, and those on diuretic therapy.
¶ Risk factors for inadequate bowel preparation include the following:

• Prior inadequate preparation
• History of constipation
• Use of medications associated with constipation (ie, tricyclic antidepressants and opioids)
• Obesity
• Diabetes mellitus
• Dementia or Parkinson disease
• Cirrhosis
• Low health literacy
• Low patient engagement

Δ For patients with history of inadequate preparation, additional measures may include: two days of clear liquids, scheduling a morning procedure, adding a second agent such as magnesium citrate if there are no contraindications.
◊ Examples of low volume preparations include low volume PEG-ELS or PEG 3350 solutions.
§ Dosing regimens: Split-dosing: One-half of the bowel preparation is given the evening before the colonoscopy and the second half is given on the day of the colonoscopy. The last dose is consumed at least two hours prior to the appointment time. Single dose, same-day: For appointments after 12 noon, a single dose preparation is an alternative. The preparation is started at least six hours prior to colonoscopy and last dose is consumed at least two hours prior to the appointment time.