Contraindications for Movicol (Macrogol/PEG)
Movicol is contraindicated in patients with intestinal obstruction, paralytic ileus, severe inflammatory bowel conditions (toxic megacolon, severe colitis), intestinal perforation or risk of perforation, and undiagnosed acute abdominal pain. 1
Absolute Contraindications
Mechanical Obstruction and Ileus
- Complete or suspected intestinal obstruction - Movicol increases luminal volume and could worsen obstruction or cause perforation 1
- Paralytic ileus - The osmotic effect cannot work effectively when peristalsis is absent 1
- Suspected or confirmed intestinal perforation - Increased luminal fluid could exacerbate peritoneal contamination 1
Severe Inflammatory Conditions
- Toxic megacolon - Risk of perforation with increased luminal distension 1
- Severe colitis or severe inflammation of the abdomen - The osmotic load may worsen inflammatory damage 1
- Severe infection of the abdomen - Similar concerns as with severe inflammation 1
Diagnostic Uncertainty
- Undiagnosed abdominal pain - Must rule out surgical causes before administering osmotic laxatives 1
Relative Contraindications and Special Precautions
Renal Impairment
- While macrogol 4000 causes virtually no net gain or loss of sodium and potassium (unlike magnesium salts which can cause hypermagnesemia), caution is still warranted in severe renal dysfunction 1
- Magnesium-containing osmotic laxatives should be avoided in renal impairment, but macrogol formulations are generally safer 1
Recent Surgery or Trauma
- Recent colorectal or gynecological surgery - Risk of anastomotic disruption 1
- Recent anal or rectal trauma - Could worsen tissue damage 1
- Recent pelvic radiotherapy - Tissue fragility increases perforation risk 1
Hematologic Conditions
- Neutropenia (WBC < 0.5 cells/μL) - While this primarily applies to enemas and suppositories, caution with any bowel manipulation is warranted 1
- Severe thrombocytopenia - Risk of bleeding with increased bowel activity 1
Important Clinical Caveats
Common pitfall: Confusing chronic constipation with early bowel obstruction. Always perform digital rectal examination and consider imaging if there is severe abdominal distension, vomiting, or complete absence of bowel movements despite treatment 1
Key distinction: Unlike stimulant laxatives or enemas, macrogol has a broader safety profile and fewer absolute contraindications, making it the preferred first-line osmotic laxative for most patients with chronic constipation 1, 2
Practical consideration: If obstruction is suspected but not confirmed, do not initiate macrogol until imaging or clinical assessment rules out mechanical causes 1