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.