In an awake adult with a protected airway and no signs of bowel obstruction, perforation, severe ileus, or hemodynamic instability, when and how should polyethylene glycol whole‑bowel irrigation be used for decontamination of ingested toxins such as iron, lithium, sustained‑release or enteric‑coated medications, heavy metals, or toxic alcohols?

Whole Bowel Irrigation with Polyethylene Glycol for Gastrointestinal Decontamination

Polyethylene glycol whole-bowel irrigation (WBI) should be considered for specific toxic ingestions—particularly sustained-release or enteric-coated medications, iron, lithium, and body packers—but should not be used routinely, as there is no convincing evidence it improves clinical outcomes in poisoned patients. 1, 2, 3

When to Use WBI: Specific Indications

Sustained-Release or Enteric-Coated Medications

• Administer WBI for patients presenting >2 hours after ingestion of sustained-release or enteric-coated drugs, when activated charcoal becomes less effective at removing tablets still in the gastrointestinal tract 1, 3
• This timing threshold is critical because delayed presentations allow tablets to move beyond the stomach where other decontamination methods are ineffective 4

Iron Ingestion

• WBI should be considered for substantial iron ingestions because iron does not bind to activated charcoal, morbidity is high, and there are no other effective gastrointestinal decontamination options 1, 3
• In severe cases, WBI can be safely continued for extended periods—one pediatric case report documented 44.3 L of polyethylene glycol-electrolyte solution (PEG-ELS) administered over 5 days (2,953 mL/kg) without adverse effects 5
• Radiographic persistence of iron tablets does not necessarily indicate ongoing absorption; rectal effluent may clear within 2 days despite visible tablets on imaging 5

Lithium and Other Non-Charcoal-Binding Toxins

• Consider WBI for lithium ingestions and other pharmaceuticals not adsorbed by activated charcoal (including potassium), particularly when substantial amounts have been ingested 1, 4
• These toxins require alternative decontamination strategies since activated charcoal is ineffective 3

Body Packers

• WBI can be used for removal of ingested packets of illicit drugs in body packers, though evidence for improved outcomes remains limited 1, 3

Administration Protocol

Dosing and Technique

• Administer PEG-ELS at 1.5-2 L/hour in adults (25-40 mL/kg/hour in children) orally or via nasogastric tube until rectal effluent is clear 1, 3
• The solution is osmotically balanced and isotonic, minimizing fluid and electrolyte shifts during administration 6, 7
• Continue irrigation until the rectal effluent runs clear, which typically indicates adequate bowel cleansing 3

Absolute Contraindications

Do not use WBI in patients with:

• Bowel obstruction, perforation, or ileus 1, 2, 3
• Hemodynamic instability 1, 3
• Compromised or unprotected airways 1, 3

Relative Contraindications and Cautions

• Use cautiously in debilitated patients or those with medical conditions that might be further compromised by large-volume fluid administration 1, 3
• Avoid concurrent administration of activated charcoal with WBI, as the irrigation may decrease charcoal effectiveness, though the clinical relevance remains uncertain 1, 3

Critical Limitations and Pitfalls

Evidence Quality

• No controlled clinical trials demonstrate that WBI improves patient outcomes, despite volunteer studies showing decreased drug bioavailability 1, 2, 3
• Observational studies confirm tablet or packet expulsion in rectal effluent, but this does not correlate with improved clinical endpoints 2

Practical Challenges

• Administration is challenging for inexperienced physicians and may be associated with serious adverse effects 2
• The procedure requires significant nursing resources and patient cooperation for hours of continuous administration 2

Common Errors to Avoid

• Do not use WBI routinely for all poisonings—reserve it for the specific indications listed above 4, 2, 3
• Do not assume radiographic clearance is necessary—clinical stability and clear rectal effluent are more important endpoints than complete radiographic clearance 5
• Do not delay WBI excessively—while it can be used later than activated charcoal, earlier administration is still preferable when indicated 1

Algorithm for Decision-Making

1. Confirm airway protection and hemodynamic stability before considering WBI 1, 3
2. Identify the specific toxin: Is it sustained-release, enteric-coated, iron, lithium, or a body-packing scenario? 1, 4
3. Assess timing: For sustained-release medications, is presentation >2 hours post-ingestion? 1, 3
4. Rule out contraindications: No bowel obstruction, perforation, ileus, or hemodynamic instability 1, 3
5. If all criteria met, initiate PEG-ELS at appropriate rate and continue until rectal effluent clears 1, 3
6. Monitor continuously for complications and clinical deterioration 2