Is an upper endoscopy (esophagogastroduodenoscopy) routine for the evaluation of chronic diarrhea?

Upper Endoscopy is NOT Routine for Chronic Diarrhea Evaluation

Upper endoscopy should not be performed routinely in the evaluation of chronic diarrhea unless there is clinical suspicion of small bowel malabsorption or upper gastrointestinal symptoms. 1

Primary Diagnostic Approach

The cornerstone investigation for chronic diarrhea is colonoscopy with ileoscopy and multiple biopsies, not upper endoscopy. 1

• Colonoscopy with biopsy yields a diagnosis in approximately 15-20% of chronic diarrhea cases, reaching up to 40% when inflammatory bowel disease is suspected. 1
• Full colonoscopy is superior to flexible sigmoidoscopy because nearly half of neoplastic lesions occur proximal to the splenic flexure. 1
• Routine ileoscopy increases diagnostic yield to 18% in non-HIV patients with diarrhea and 36% in suspected IBD cases with normal colonoscopy. 1

When Upper Endoscopy IS Indicated

Upper endoscopy becomes appropriate only in specific clinical scenarios:

Suspected Malabsorption

• Perform upper endoscopy with distal duodenal biopsies when small bowel malabsorption is suspected clinically, even with negative celiac serology (antiendomysium IgA antibodies). 1
• This evaluates for celiac disease and other small bowel enteropathies that can present with chronic diarrhea. 1

Pediatric and Adolescent IBD

• Upper endoscopy is mandatory in pediatric populations with suspected IBD for accurate disease classification and to differentiate Crohn's disease from ulcerative colitis. 1
• Growth failure in children necessitates upper GI evaluation. 1

Adult IBD with Upper GI Symptoms

• In adult IBD patients, upper endoscopy is indicated when dyspepsia or upper abdominal pain is present. 1
• Upper GI tract inflammation occurs in Crohn's disease even without localizing symptoms, but routine screening in asymptomatic adults remains unclear. 1

Critical Pitfalls to Avoid

Do not confuse this with GERD evaluation: The evidence about upper endoscopy for GERD screening 1, 2 is irrelevant to chronic diarrhea workup and should not influence decision-making in diarrheal disease. 1

Ensure adequate tissue sampling: When colonoscopy is performed, obtain multiple biopsies (minimum of two) from six segments: terminal ileum, ascending colon, transverse colon, descending colon, sigmoid, and rectum—including normal-appearing mucosa. 1, 3

• This is essential because microscopic colitis, which causes 15% of chronic diarrhea cases, appears endoscopically normal but requires histological diagnosis. 1
• Rectosigmoid biopsies alone have a 34-43% false negative rate for microscopic colitis; right-sided colonic biopsies are necessary. 1

Diagnostic Yield Reality

The diagnostic yield of upper endoscopy in unselected chronic diarrhea patients is poorly documented and likely low. 1

• Guidelines explicitly state "there is little information on the diagnostic yield of upper gastrointestinal endoscopy in patients whose diarrhea is suspected to be due to malabsorption." 1
• The yield varies dramatically based on patient selection, referral patterns, and clinical suspicion for specific diagnoses. 1

Algorithmic Approach

1. Start with colonoscopy and ileoscopy with multiple biopsies from all segments (including normal-appearing mucosa). 1

2. Add upper endoscopy with duodenal biopsies only if:

   • Clinical features suggest malabsorption (steatorrhea, weight loss, nutritional deficiencies). 1
   • Patient is pediatric/adolescent with suspected IBD. 1
   • Adult IBD patient has upper GI symptoms. 1

3. Do not perform upper endoscopy routinely in asymptomatic adults with chronic diarrhea and no malabsorption features. 1