3
Table 1. Basic Approach to Assessing Diarrhea and Concern for
Malabsorption
FIRST
Carefully evaluate for common causes of diarrhea (e.g., medication
side effects, sugar alcohols from liquid medication, and C. difficile)
and, finally, malabsorption.
Second
Classify diarrhea as inflammatory, secretory, or malabsorptive.
Third
Consider underlying GI disorders (pancreatic or cholestatic process,
celiac disease, microscopic colitis, IBD, small intestinal bacterial
overgrowth).
Fourth
Evaluate for fat malabsorption (see Table 3).
Table 2. Potential Causes of Fat Malabsorption
Bile Salt Deficiency-Related Diagnoses
Impaired/inadequate
mixing of bile with fat
• Biliary obstruction
• Surgical diversion (e.g.,
gastric bypass and
Whipple procedure)
• Percutaneous biliary drains
• Post-cholecystectomy
Impaired synthesis/
inadequate production
• Cirrhosis
• Chronic cholestasis
• Ileal disease
• Ileal resection (typically
>100 cm)
• Bacterial overgrowth
Pancreatic Insufficiency/Deficiency
Failure to produce
pancreatic enzymes
• Pancreatitis
• Cystic fibrosis
• Celiac sprue
• Diabetes
• Surgical pancreatectomy
• Normal aging
Failure to deliver
pancreatic enzymes
• Benign pancreatic duct obstruction
• Malignant duct obstructions
• Surgical diversions
• Bowel obstruction distal to pancreatic secretions
Inactivation of
pancreatic enzymes
• Gastric hypersecretion first 6–12 months of short bowel
syndrome due to resection
• Zollinger Ellison syndrome
KEY POINT: Infections associated with diarrhea are exceedingly rare causes of
malabsorptive diarrhea. In the inpatient setting, there is a 6% yield of positive tests
with significant concern for false positive tests. Clostridium difficile-assocated diarrhea
however, should always be ruled out.
