Small-bowel capsule endoscopy in patients with unexplained chronic abdominal pain: a systematic review

Background: Patients frequently consult primary care physicians and gastroenterologists when experiencing chronic abdominal pain. Although its diagnostic efficacy in these settings is uncertain, small-bowel capsule endoscopy (SBCE) has been used to evaluate the unexplained reasons for abdominal pain. Objective: To evaluate the diagnostic yield of SBCE in patients with unexplained chronic abdominal pain. Design: We performed a retrospective review of publications reporting the diagnostic yield of SBCE in patients with unexplained chronic abdominal pain and calculated the overall diagnostic yield. Setting: Two investigators independently searched studies from databases and analyzed the results. Patients: A total of 1520 patients from 21 studies were included. Interventions: Small-bowel capsule endoscopy. Main Outcome Measurements: Per-patient diagnostic yield, with 95% confidence intervals (CI), was evaluated by a random-effect model. Clear categorical analysis also was performed. Results: The pooled diagnostic yield of SBCE in patients with unexplained chronic abdominal pain was 20.9% (95% CI, 15.9%-25.9%), with high heterogeneity (I-2 = 80.0%; P < .001). Inflammatory lesions were the most common (78.3%) positive findings, followed by tumors (9.0%). Limitations: Heterogeneity among studies, retrospective design, variable chronicity of abdominal pain, and different previous examinations before SBCE. Conclusion: SBCE provides a noninvasive diagnostic tool for patients with unexplained chronic abdominal pain, but the diagnostic yield is limited (20.9%). Among patients with positive findings, inflammatory lesions are the most common.