AIM:To evaluate the effectiveness of wireless capsuleendoscopy in patients with suspected Crohn’s disease (CD)of the small bowel undetected by conventional modalities,and to determine the diagnostic yield of M2A Given Capsule.METHODS:From May 2002 to April 2003,we prospectivelyexamined 20 patients with suspected CD by capsuleendoscopy.The patients had the following features:abdominal pain,weight loss,positive fecal occult bloodtest,iron deficiency anaemia,diarrhoea and fever.All thepatients had normal results in small bowel series (SBS)and in upper and lower gastrointestinal endoscopy beforethey were examined.Mean duration of symptoms beforediagnosis was 6.5 years.RESULTS:Of the 20 patients,13 (65%) were diagnosedas CD of the small bowel according to the findings of M2AGiven Capsule.The findings detected by the capsule weremucosal erosions (2 patients),aphthas (5 patients),nodularity (1 patient),large ulcers (2 patients),andulcerated stenosis (3 patients).The distribution of thelesions was mainly in the distal part of the small bowel,and the mild degree of lesions was 54%.CONCLUSION:Wireless capsule endoscopy is effective indiagnosing patients with suspected CD undetected byconventional diagnostic methods.It can be used to detectearly lesions in the small bowel of patients with CD.