What is the recommended procedure for an adult or pediatric patient with suspected small bowel pathology, such as Crohn's disease or celiac disease, presenting with symptoms like abdominal pain, diarrhea, or weight loss?

Small Bowel Follow-Through: Not Recommended for Modern Diagnosis

Small bowel follow-through (SBFT) should not be used as a first-line diagnostic modality for suspected Crohn's disease or other small bowel pathology—capsule endoscopy, MR enterography, or CT enterography are superior alternatives. 1

Why SBFT Is Obsolete for Most Indications

Poor Diagnostic Performance

• SBFT has significantly lower diagnostic yield compared to modern imaging, detecting inflammatory lesions in only 57-67% of cases versus 96-97% with capsule endoscopy combined with ileocolonoscopy 1, 2
• The two-dimensional perspective causes pathology to be obscured by overlapping bowel loops, limiting accuracy for detecting active disease 1
• SBFT has poor specificity for Crohn's disease, as small lesions may represent other conditions, and diagnostic yield is particularly poor in patients with only abdominal pain or diarrhea without inflammatory biomarkers 1

Direct Comparative Evidence

• In a prospective blinded trial of 80 patients with suspected Crohn's disease, capsule endoscopy plus ileocolonoscopy detected 107 of 110 inflammatory lesions (97.3%), while SBFT plus ileocolonoscopy detected only 63 lesions (57.3%) 2
• No diagnoses were made based on SBFT findings alone in this cohort 2
• SBFT sensitivity for active small bowel Crohn's disease was only 65%, compared to 83% for both capsule endoscopy and CT enterography 3

Recommended Diagnostic Algorithm for Suspected Small Bowel Pathology

For Suspected Crohn's Disease

1. Start with ileocolonoscopy with segmental biopsies as the first-line investigation when Crohn's disease is clinically suspected (chronic diarrhea >6 weeks, abdominal pain, weight loss, elevated inflammatory markers or fecal calprotectin) 4, 5, 6

2. If ileocolonoscopy is negative or inconclusive, proceed to capsule endoscopy of the small bowel 4, 5

   • This represents a strong recommendation despite very low quality evidence, based on superior diagnostic yield and lack of appropriate alternatives 4
   • Capsule endoscopy detected additional lesions in 50-86% of patients with known CD and influenced disease management 4

3. Use MR enterography or CT enterography instead of capsule endoscopy when obstructive features or known stenosis are present 1, 5

   • Cross-sectional imaging can identify obstructive strictures, assess transmural disease extent, and detect extramural complications 1
   • MR enterography is preferred as first-line imaging because it avoids ionizing radiation and has similar diagnostic accuracy to CT enterography 5

For Obscure GI Bleeding

• Capsule endoscopy is the next diagnostic step after negative EGD and colonoscopy, ideally performed as soon as possible 1

Limited Remaining Uses for SBFT

Water-Soluble Contrast Challenge for Small Bowel Obstruction

• The only clinically relevant modern indication for SBFT is a water-soluble contrast challenge to predict success of conservative management in small bowel obstruction 1
• Administer contrast agent with follow-up radiographs at 8 and 24 hours 1
• Patients in whom contrast reaches the colon by 24 hours rarely require surgery, making this a useful triage tool 1

Preoperative Anatomy Delineation

• SBFT may have a limited role in delineating preoperative anatomy for surgeons, depending on institutional preference, though this use has markedly declined 1

Critical Contraindications and Pitfalls

Absolute Contraindications

• Barium-based SBFT is contraindicated in suspected or confirmed bowel perforation due to risk of severe chemical peritonitis 1
• SBFT should not be performed when high-grade obstruction is suspected, as it provides inadequate information for surgical decision-making 1

Clinical Pitfalls to Avoid

• Do not order SBFT as initial imaging for suspected Crohn's disease—you will miss the majority of inflammatory lesions and delay appropriate diagnosis 1, 2
• Do not rely on SBFT alone to rule out small bowel pathology in patients with persistent symptoms and elevated inflammatory markers 1
• Recognize that 17% of patients may have asymptomatic partial small bowel obstruction on cross-sectional imaging, which would contraindicate subsequent capsule endoscopy 3

Special Considerations for Celiac Disease

For suspected celiac disease, there is generally no need for radiological small bowel imaging in uncomplicated cases 7. However, cross-sectional enteroclysis techniques (MR or CT enterography) are important for investigating suspected complicated celiac disease, including refractory celiac disease type II and malignant complications such as enteropathy-associated T-cell lymphoma 7.