- Colonoscopy is used widely for colorectal cancer (CRC) screening and surveillance and the diagnostic evaluation of symptoms and other positive CRC screening tests.
- The success of colonoscopy is linked closely to the adequacy of preprocedure bowel cleansing.
- Up to 20%–25% of all colonoscopies are reported to have an inadequate bowel preparation. The Multi-Society Task Force sets a new benchmark that at least 85% of all colonoscopies are rated as adequate on a per-physician basis.
- Adverse consequences of ineffective bowel preparation include lower adenoma detection rates, longer procedural time, lower cecal intubation rates, increased electrocautery risk, and shorter intervals between examinations.
- Consequently, the choice of a bowel cleansing regimen should be based on cleansing efficacy first and patient tolerability second.
GRADE Strength of Recommendations and Implications
|Grade||Implications of strong and conditional (weak) guideline recommendations|
Reprinted with permission from Sultan et al. Clin Gastroenterol Hepatol. 2013;11:329–332.
- Preliminary assessment of preparation quality should be made in the rectosigmoid colon, and if the indication is screening or surveillance and the preparation clearly is inadequate to allow polyp detection >5 mm, the procedure should be either terminated and rescheduled or an attempt should be made at additional bowel cleansing strategies that can be delivered without cancelling the procedure that day. (Strong; Low Quality of Evidence)
- If the colonoscopy is complete to cecum, and the preparation ultimately is deemed inadequate, then the examination should be repeated, generally with a more aggressive preparation regimen, within 1 year. Intervals <1 year are indicated when advanced neoplasia is detected and there is inadequate preparation. (Strong; Low Quality of Evidence)
- If the preparation is deemed adequate and the colonoscopy is completed then the guideline recommendations for screening or surveillance should be followed. (Strong; High Quality of Evidence)
Dosing and Timing of Colon Cleansing Regimens
- Use of a split-dose bowel cleansing regimen is strongly recommended for elective colonoscopy. (Strong; High Quality of Evidence)
- A same-day regimen is an acceptable alternative to split dosing, especially for patients undergoing an afternoon examination. (Strong; High Quality of Evidence)
- The second dose of split preparation ideally should begin 4–6 hours before the time of colonoscopy with completion of the last dose at least 2 hours before the procedure time. (Strong; Moderate Quality of Evidence)
Diet During Bowel Cleansing
- By using a split-dose bowel cleansing regimen, diet recommendations can include either low-residue or full liquids until the evening on the day before colonoscopy. (Weak; Moderate Quality of Evidence)
Usefulness of Patient Education and Navigators for Optimizing Preparation Results
- Health care professionals should provide both oral and written patient education instructions for all components of the colonoscopy preparation and emphasize the importance of compliance. (Strong; Moderate Quality of Evidence)
- The physician performing the colonoscopy should ensure that appropriate support and process measures are in place for patients to achieve adequate colonoscopy preparation quality. (Strong; Low Quality of Evidence)
Rating the Quality of Bowel Preparation During Colonoscopy
- Adequacy of bowel preparation should be assessed after all appropriate efforts to clear residual debris have been completed. (Strong; Low Quality of Evidence)
- Measurement of the rate of adequate colon cleansing should be conducted routinely. (Strong; Moderate Quality of Evidence)
- Adequate preparation, defined as cleansing that allows a recommendation of a screening or surveillance interval appropriate to the findings of the examination, should be achieved in 85% or more of all examinations on a per-physician basis. (Strong; Low Quality of Evidence)
- Selection of a bowel-cleansing regimen should take into consideration the patient’s medical history, medications, and, when available, the adequacy of bowel preparation reported from prior colonoscopies. (Strong; Moderate Quality of Evidence)
- A split-dose regimen of 4 L PEG-ELS provides high-quality bowel cleansing. (Strong; High Quality of Evidence)
- In healthy nonconstipated individuals, a 4-L PEG-ELS formulation produces a bowel-cleansing quality that is not superior to a lower-volume PEG formulation. (Strong; High Quality of Evidence)
OTC Non-FDA-Approved Preparations
- The OTC bowel cleansing agents have variable efficacy that ranges from adequate to superior, depending on the agent, dose, timing of administration, and whether it is used alone or in combination. Regardless of the agent, the efficacy and tolerability are enhanced
with a split-dose regimen. (Strong; Moderate Quality of Evidence)
- Although the OTC purgatives generally are safe, caution is required when using these agents in certain populations — for example, magnesium-based preparations (both OTC and FDA-approved formulations) should be avoided in patients with chronic kidney disease. (Weak; Very Low Quality of Evidence)
Adjuncts to Colon Cleansing Before Colonoscopy
- The routine use of adjunctive agents for bowel cleansing before colonoscopy is NOT recommended. (Weak; Moderate Quality of Evidence)
Differences in Patient Preference/Willingness to Repeat Comparisons
- Split-dose bowel cleansing is associated with greater willingness to repeat regimen compared with the day before regimen. (Strong; High Quality of Evidence)
- The use of low-volume bowel cleansing agents is associated with greater willingness to undergo a repeat colonoscopy. (Strong; High Quality of Evidence)
Selection of Bowel Preparation in Specific Populations
- There is insufficient evidence to recommend specific bowel preparation regimens for elderly persons. However, we recommend that NaP preparations be avoided in this population. (Strong; Low Quality of Evidence)
- There is insufficient evidence to recommend specific bowel preparation regimens for children and adolescents undergoing colonoscopy. However, we recommend that NaP preparations should not be used in children younger than age 12 or in those with risk factors for complications from this medication. (Strong; Very Low Quality of Evidence)
- NaP should be avoided in patients with known or suspected inflammatory bowel disease. (Weak; Very Low Quality of Evidence)
- Additional bowel purgatives should be considered in patients with risk factors for inadequate preparation (eg, patients with a prior inadequate preparation, history of constipation, use of opioids or other constipating medications, prior colon resection, diabetes mellitus, or spinal cord injury) (Weak; Low Quality of Evidence)
- Note: A detailed discussion of patient factors that predict inadequate preparation is presented in Appendix C of the full text guideline (Johnson DA et al. Gastroenterology 2014;147:903–924).
- Low-volume preparations or extended time delivery for high-volume preparations are recommended for patients after bariatric surgery. (Weak; Very Low Quality of Evidence)
- Tap water enemas should be used to prepare the colon for sigmoidoscopy in pregnant women. (Strong; Very Low Quality of Evidence)
- There is insufficient evidence to recommend specific regimens for persons with a history of spinal cord injury; additional bowel purgatives should be considered. (Weak; Very Low Quality of Evidence)
Salvage Options for Inadequate Preparation
- Large-volume enemas can be attempted for patients who, presenting on the day of colonoscopy, report brown effluent despite compliance with the prescribed colon-cleansing regimen. (Weak; Very Low Quality of Evidence)
- Through-the-scope enema with completion colonoscopy on the same day can be considered, especially for those patients who receive propofol sedation. (Weak; Very Low Quality of Evidence)
- Waking the patient entirely from sedation and continuing with further oral ingestion of cathartic with same-day or next-day colonoscopy has been associated with better outcomes than delayed colonoscopy.
(Weak; Low Quality of Evidence)