What are oral bowel regimen drugs?

From the Guidelines

For optimal bowel preparation before colonoscopy, a split-dose regimen is strongly recommended, with the second dose ideally starting 4–6 hours before the procedure and completion of the last dose at least 2 hours before the procedure time 1. When selecting a bowel-cleansing regimen, consideration should be given to the patient’s medical history, medications, and prior colonoscopy results, if available 1. Key options for bowel preparation include:

• Polyethylene glycol–electrolyte lavage solution (PEG-ELS)–based cleansing agents, available in high or low volume formulations
• Low-volume agents such as oral sulfate solution (OSS), sodium picosulfate/magnesium citrate, and combinations like PEG-ELS and OSS
• For general constipation management, a stepwise approach can be used, starting with osmotic laxatives like polyethylene glycol, followed by stimulant laxatives if necessary, and stool softeners for more severe cases. It's crucial to maintain adequate hydration and gradually increase dietary fiber. The choice of regimen should be tailored to the individual's needs and medical history, ensuring the best possible outcome in terms of bowel cleansing quality and patient comfort. In cases where constipation is the primary concern rather than bowel preparation for a procedure, the approach may differ, focusing on lifestyle adjustments and less intensive medication regimens. However, for colonoscopy preparation, the split-dose regimen remains the preferred method due to its high-quality evidence supporting its effectiveness 1.

From the FDA Drug Label

USE • relieves occasional constipation (irregularity) • generally produces a bowel movement in 1 to 3 days The polyethylene glycol (PO) is used as an oral bowel regiment drug to relieve occasional constipation and produce a bowel movement.

• The drug generally produces a bowel movement in 1 to 3 days 2

From the Research

Oral Bowel Regiment Drugs

• The effectiveness of different oral bowel preparation regimens for colonoscopy has been studied in various trials 3, 4, 5, 6, 7.
• A study comparing same-day morning polyethylene glycol (PEG) regimen with low-volume split-dose PEG regimen found that the same-day morning regimen was more effective in achieving adequate bowel preparation 3.
• Another study compared a new hybrid preparation consisting of oral sulfate solution (OSS) plus sulfate-free electrolyte lavage solution (SF-ELS) with 2 low-volume preparations based on PEG electrolyte lavage solution (PEG-ELS) and found that OSS plus SF-ELS was noninferior to PEG-EA 4.
• A meta-analysis of 47 trials found that split-dose preparations provided significantly better colon cleansing than day-before preparations 5.
• A study comparing oral sodium phosphate solution with PEG-based solution for bowel preparation in children found that oral sodium phosphate solution was better tolerated but caused hyperphosphatemia 6.
• A prospective comparison of oral sodium phosphate versus sulfate-free PEG electrolyte lavage solution in outpatient preparation for colonoscopy found that both preparations were equally well tolerated and effective, but sodium phosphate preparation caused significant alterations in serum electrolyte levels 7.

Types of Oral Bowel Preparation Regimens

• Polyethylene glycol (PEG) based solutions 3, 4, 5
• Oral sodium phosphate solutions 6, 7
• Oral sulfate solution (OSS) plus sulfate-free electrolyte lavage solution (SF-ELS) 4
• Split-dose preparations 3, 4, 5
• Same-day morning preparations 3

Efficacy and Tolerability

• The efficacy of bowel preparation regimens can be assessed using the Boston Bowel Preparation Scale (BBPS) 3.
• Tolerability can be assessed by recording symptoms such as nausea, vomiting, bloating, and abdominal pain 3, 4.
• Patient satisfaction and willingness to repeat the preparation can also be used to evaluate the tolerability of a regimen 3, 4.