Abstract： Background X-ray of the digestive tract and radionuclide examination could not accurately detect diseases of the small intestine.Double-balloon enteroscopy has been used to increase the detection rate of these diseases in addition to endoscopic biopsy and therapy.The purpose of this study was to determine the value of double-balloon enteroscopy in the diagnosis and treatment of diseases of the small intestine.Methods A total of 258 double-balloon enteroscopies via the mouth and/or anus were performed in 208 patients.If no lesion was detected on one side(mouth or anus),examination on the other side (anus or mouth) was made.If active small intestinal bleeding was detected,endoscopic hemostasis was done to treat the bleeding.Results In the 208 patients,50 were subjected to double-balloon enteroscopy via both mouth and anus.Lesions were detected in 151 patients,giving a rate of 72.6%(151/208).The detection rates for obscure digestive tract bleeding,diarrhea,abdominal pain and weight loss were 90.2%(92/102),64.9%(24/37),48.5%(16/33) and 43.3%(13/30),respectively.Lesions of the 151 patients were confirmed by endoscopic biopsy,surgery,clinical studies,and follow-up.In the 102 patients with bleeding of the digestive tract,active bleeding was detected in 27 patients.Endoscopic hemostasis was successful in 25 of them (92.6%,25/27).No serious complications occurred in all the patients,the average time for the procedure was 100 minutes.Conclusions Double-balloon enteroscopy is safe,effective in the diagnosis of diseases of the small intestine in addition to endoscopic therapy.