Managing Diarrhea in Tube-Fed Patients
When diarrhea develops in tube-fed patients, the feeding formula itself is rarely the culprit—medications (particularly those containing sorbitol), antibiotics, and infectious causes are responsible in the vast majority of cases. 1, 2
Initial Diagnostic Approach
Stop All Potential Offending Medications First
- Immediately discontinue all laxatives, including magnesium-containing antacids and medications with sorbitol or other active fillers 1
- Review all medications for diarrhea-inducing agents: H2 blockers, proton pump inhibitors, antibiotics, antiarrhythmics, antihypertensives, and NSAIDs 1
- Liquid medication formulations frequently contain sorbitol, which causes osmotic diarrhea in 61% of tube-fed patients with diarrhea 2
Send Stool Studies
- Check stool samples for Clostridium difficile toxin whenever diarrhea develops, as 20-50% of antibiotic-associated diarrhea in tube-fed patients is due to C. difficile 1
- Calculate stool osmotic gap (stool osmolality - 2[Na + K]) to distinguish osmotic from secretory diarrhea—a gap >100 mmol/L indicates osmotic diarrhea 2
- Send fecal leukocytes to assess for inflammatory causes 2
Address Infection Control and Contamination
Implement Strict Feeding Hygiene Protocols
- Discard administration sets and nutrient containers every 24 hours, as bacterial contamination of feeds can cause diarrhea, sepsis, and pneumonia 1
- Never allow any part of the delivery system or feed to contact hands, clothes, skin, or non-disinfected surfaces 1
- Do not decant feeds before use 1
- Use proper handwashing and clean gloves before handling feeding tubes 1
Feeding Formula Modifications (Only After Above Steps)
Consider Formula Type Changes
- Fiber-containing formulas may help normalize transit times, though evidence for reducing diarrhea is limited since most diarrhea is unrelated to the feed itself 1
- Standard isotonic formulas are appropriate for most patients and are not associated with increased diarrhea risk compared to hypertonic formulas 3
- Feed temperature (refrigerated vs. warmed) does not significantly alter gastrointestinal complications 1
Adjust Feeding Rate and Method
- Reduce feeding rate temporarily if diarrhea persists after addressing medications and infections 1
- Consider implementing feeding breaks of 4-8 hours to allow gastric pH to fall and reduce bacterial overgrowth 4
- Continuous pump feeding may be better tolerated initially than bolus feeding in some patients 1
Common Pitfalls to Avoid
Do Not Assume the Formula is the Problem
- In prospective studies, tube feeding formula was responsible for diarrhea in only 21% of cases, while medications caused 61% and C. difficile caused 17% 2
- Hypoalbuminemia is associated with diarrhea but does not cause it—both reflect systemic inflammatory response rather than direct causation 1
- Albumin supplementation does not correct tube feeding-associated diarrhea 1
Do Not Rely on Subjective Assessment
- Subjective patient reports of diarrhea are unreliable—objective stool weight measurement (>200g/day) or frequency (≥3 liquid stools/day) should define diarrhea 5, 3
- Many patients report diarrhea despite producing <250g stool/day, which is within normal limits 5
Pharmacologic Management (If Needed)
Antidiarrheal Agents
- Loperamide can be used at recommended doses (initial 4mg, then 2mg after each unformed stool, maximum 16mg/day) once infectious causes are excluded 6
- Avoid loperamide in patients taking QT-prolonging drugs (Class IA/III antiarrhythmics, certain antipsychotics, antibiotics like moxifloxacin) due to cardiac arrhythmia risk 6
- For coeliac plexus block-related diarrhea, consider loperamide, hyoscine butylbromide, or octreotide 1
Monitoring Requirements
- Check gastric residuals every 4 hours initially; if >200mL, review feeding regimen 1, 4
- Monitor fluid status and electrolytes (sodium, potassium, magnesium, phosphate) closely, especially in malnourished patients at risk for refeeding syndrome 1
- Ensure adequate fluid and electrolyte replacement, as tube feeding does not preclude this need 6