1. A method for processing in-vivo information, the method comprising: receiving, at a data processor, data generated by a swallowable in-vivo device traversing a gastrointestinal tract, the data comprising a set of in-vivo images of the gastrointestinal tract; the data processor comparing values of an image from the received set of images to a reference value of blood; the data processor calculating an adaptive reference value of healthy tissue for the image, based on averaging parameters of images of healthy tissue, the images previous to the image in the received set of images; the data processor comparing values of the image to the adaptive reference value of healthy tissue; and based on the comparisons, the data processor generating a probability indication of a presence of blood in the image.