Objective        To evaluate the diagnostic value of OMOM capsule endoscopy in patients with unexplained abdominal pain.        Methods         From Oct 2005 to Sep 2011

OMOM capsule endoscopy was used in 159 patients with chronic abdominal pain (abdominal pain group) and 268 healthy examinees without any symptoms (healthy people group). The diagnoses by OMOM capsule endoscopy were recorded and compared statistically.        Results        For small intestinal mucosa lesions in the abdominal pain group

the diagnostic positive rate was 63.1% (99/157)

which was significantly higher than that in the healthy people group (18.7%

50/268) (P0.05). The 99 patients with small intestinal mucosa lesions in the abdominal pain group included 39 patients suffered from non-specific inflammation of small intestinal mucosa (24.8%)

9 patients with small intestinal vascular malformation (5.7%)

9 patients with small intestinal tumor (5.7%)

8 patients with small intestinal lymphoid hyperplasia (5.1%)，6 patients with small intestinal polyp (3.8%)

6 patients with ancylostomiasis (3.8%)

5 patients with small intestinal ulcer (3.2%)

5 cases of Crohn disease (3.2%)

4 patients with small intestinal tuberculosis (2.5%)

3 patients with ascarid (1.9%)

3 patients with small intestinal xanthoma (1.9%) and 2 patients with small intestinal lipoma (1.3%). About 36.9% (58/157) patients in the abdominal pain group showed no small intestine abnormity.        Conclusion       OMOM capsule endoscopy is a safe procedure and a valuable tool in etiological diagnosis of unexplained abdominal pain.