What is the protocol for prescribing a bowel cleanse for constipation, also known as bowel preparation or bowel cleanout, using medications such as polyethylene glycol (PEG) or bisacodyl?

From the Guidelines

For a bowel clean out to address constipation, I recommend a stepwise approach using a combination of oral laxatives, starting with polyethylene glycol (MiraLAX) at a dose of 1-1.5 g/kg/day (maximum 17g per dose) mixed in 8 ounces of clear liquid, given once or twice daily for 3-4 days, as this approach is supported by the most recent and highest quality evidence 1.

Key Considerations

• The 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 1.
• A split-dose regimen of 4 L PEG-ELS provides high-quality bowel cleansing, but for constipation, a lower volume may be sufficient and more comfortable for the patient 1.
• Laxatives work via a variety of mechanisms to improve the frequency of bowel movements, the consistency of stool, or to facilitate defecation, and osmotic laxatives like polyethylene glycol (PEG) are effective in drawing water into the gut to hydrate the stool 1.

Instructions for Families

• Ensure the child drinks plenty of fluids during the clean out process to help soften the stool and make it easier to pass.
• Maintain a diary of bowel movements to track progress and adjust the treatment plan as needed.
• Continue the clean out process until the child is passing watery stool, which indicates that the bowel is clear.
• Explain that initial discomfort, increased gas, or mild cramping is normal, but advise families to contact their healthcare provider if severe pain, vomiting, or bleeding occurs during the clean out process.

Maintenance Regimen

• After the clean out, a maintenance regimen with daily MiraLAX (0.5-1 g/kg/day) is typically needed for several weeks or months to prevent recurrence while establishing healthy bowel habits.
• The goal of the maintenance regimen is to prevent constipation from recurring and to establish a regular bowel routine, which can help improve the child's overall quality of life.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Bowel Clean Out Instructions

To prescribe a "bowel clean out" for constipation, the following steps can be taken:

• A low-fiber diet for 72 hours and a liquid diet for 24 hours can be recommended to prepare the bowel for cleansing 2
• Bisacodyl (10 mg) can be taken in the evening before the colonoscopy, and a split dose of polyethylene glycol (1.5 L in the evening before and 1.5 L in the morning on the day of the colonoscopy) can be used for bowel preparation 2
• The use of polyethylene glycol solution has been shown to be safer and more effective than mannitol solution for bowel preparation 3
• A split-dose regimen of bowel preparation has been found to be more effective than a non-split-dose regimen, with an adequate preparation rate of 85% compared to 63% 4

Instructions for Families

When instructing families regarding bowel clean out, the following points can be emphasized:

• The importance of following a low-fiber diet and liquid diet before the colonoscopy to ensure effective bowel preparation 2
• The need to take bisacodyl and polyethylene glycol as directed to achieve adequate bowel cleansing 2
• The potential side effects of bowel preparation, such as nausea, vomiting, and abdominal pain, and the importance of reporting any severe symptoms 3
• The importance of compliance with the bowel preparation regimen to ensure effective colonoscopy and detection of any potential health issues 4