Small-bowel transit time in capsule endoscopy: a determinant factor for the diagnosis of small-bowel bleeding

Background: small-bowel capsule endoscopy (SBCE) is the gold standard for the study of small-bowel bleeding (SBB). Recent studies suggest that longer small-bowel transit times (SBTT) may be associated with a higher diagnostic yield of SBCE. Aim: the aim of the study was to investigate if longer SBTT is a predictive factor of positive findings on SBCE in a population that underwent SBCE for suspected SBB. Methods: a retrospective single-center study including consecutive SBCEs between May 2012 and May 2019, due to suspected SBB. A positive SBCE was considered in the presence of lesions with high bleeding potential such as ulcers, angioectasias, and tumors (P2 lesions, according to the Saurin classification). Results: we included 372 patients, 65.9 % female, with a median age of 67 (IQR: 19-97) years. We observed that patients with P2 lesions (n = 131; 35.2 %) in SBCE exhibited a longer SBTT (p = 0.01), were older (p < 0.001), were more frequently male (p = 0.019), and suffered more frequently from arterial blood hypertension (p = 0.011), diabetes (p = 0.042), chronic kidney disease (p = 0.003), and heart failure (p = 0.001). In the logistic analysis, significant predictive factors for the presence of P2 lesions included age (OR: 1.027; 95 % CI: 1.009-1.045; p = 0.004), SBTT (OR: 1.002; 95 % CI: 1.001-1.005; p = 0.029), and male gender (OR: 1.588; 95 % CI: 1.001-2.534; p = 0.049). Conclusions: patients with longer SBTT had higher rates of lesions with high bleeding potential (P2). SBTT along with previously well-defined factors such as age and male gender were the only independent predictive factors for the presence of P2 lesions. These findings may suggest that a slower passage of the capsule through the small bowel may allow a better diagnostic yield for significant lesions.