Colonic preparation before colonoscopy in constipated and non-constipated patients: a randomized study

Area of Science:

• Gastroenterology
• Colorectal Surgery
• Pharmacology

Background:

• Effective colonic cleansing is crucial for outpatient colonoscopy success.
• Various bowel preparation regimens, including sodium phosphate (NaP) and polyethylene glycol (PEG), are used.
• The role of adjuncts like bisacodyl in improving preparation quality and compliance requires further investigation.

Purpose of the Study:

• To compare the efficacy of different doses of NaP and PEG, alone or with bisacodyl, for colonic cleansing.
• To evaluate tolerability, compliance, and side effects associated with these preparations in constipated and non-constipated patients.
• To assess endoscopist and patient perceptions of colonic preparation quality.

Main Methods:

• A randomized, blinded study involving 349 adult outpatients scheduled for colonoscopy.
• Patients received one of four preparations: NaP (90 mL), NaP (45 mL) + bisacodyl (20 mg), PEG (4 L), or PEG (2 L) + bisacodyl (20 mg).
• Primary outcome was colonic cleansing efficacy; secondary outcomes included tolerability, compliance, and adverse events.

Main Results:

• Overall colonic cleansing efficacy was similar across all preparation groups.
• NaP preparations demonstrated higher patient compliance, particularly the NaP + bisacodyl combination (100%).
• In constipated patients, NaP + bisacodyl showed superior cleansing efficacy (95%) compared to PEG (66%). Bisacodyl was associated with abdominal pain, while NaP + bisacodyl was linked to insomnia.

Conclusions:

• NaP preparations enhance compliance in non-constipated patients, though bisacodyl may cause adverse effects.
• For constipated patients, the combination of NaP plus bisacodyl is the most effective colonic preparation.
• While overall cleansing efficacy is comparable, patient-specific factors and constipation status influence the choice of bowel preparation.