Background/aim: Small bowel capsule endoscopy (SBCE) is currently a fundamental tool in the etiological study of obscure gastrointestinal bleeding (OGIB). However, the impact of a negative exam and the risk of rebleeding are not entirely known. The aim of this study was to evaluate the outcomes of patients with OGIB and a negative SBCE examination in terms of follow-up duration, additional diagnostic studies, and achievement of a diagnosis as well as to assess the incidence of rebleeding and possible associated factors.
Materials and methods: We retrospectively analyzed 256 patients who consecutively underwent an SBCE examination for the study of OGIB between April 2006 and December 2011, and then selected the 79 whose results excluded potentially bleeding lesions. Eleven patients were lost to follow-up and the remaining 68 were eligible for a nested case-control analysis. Pre-SBCE and post-SBCE information was collected, including follow-up interval and incidence of rebleeding, defined as admission to the hospital for symptomatic anemia, need for blood transfusion, decrease in hemoglobin value of greater than 2 g/dl, or evidence of melena or hematochezia. Univariate analysis included age, sex, OGIB presentation (occult or visible), hemoglobin levels at presentation, and comorbidities.
Results: In the 68 patients analyzed, the mean age was 52±18 years and 61.8% were women. The OGIB was occult in 54 patients (79.4%) and overt in 14 patients (20.6%). Patients were followed up for an average of 32 months. Thirty-nine patients (57.4%) underwent further diagnostic investigations during the period of follow-up and a cause for the gastrointestinal bleeding was found in five of them. Rebleeding was documented in 16 (23.5%) patients, occurring on average 15±13.8 months after the SBCE. Male sex was associated significantly with higher incidence of rebleeding (P=0.004).
Conclusion: Approximately one quarter of patients with OGIB and negative SBCE examination will experience rebleeding, with higher incidence among men; thus, a negative SBCE in this setting is not reassuring. As the vast majority of rebleeding episodes seem to occur within the following 2 years after SBCE, the maintenance of regular medical surveillance during the above-mentioned period of time after a negative SBCE seems advisable.