1. A method for displaying in-vivo information, the method comprising: receiving at a data processor data generated by a swallowable in-vivo device traversing a GI tract, the data comprising a set of in-vivo images of the GI tract; for each image of said set, the data processor calculating: (i) a first distance between a colorimetric value of the image and a first reference value, wherein the first reference value corresponds to predetermined colorimetric values obtained from in-vivo images showing blood in the GI tract, and (ii) a second distance between said colorimetric value of the image and a second reference value, wherein the second reference value corresponds to colorimetric values obtained from in-vivo images showing healthy GI tract tissue; the data processor further, based on the first distance and the second distance, causing to be displayed a probability indication of presence of blood corresponding to a position in the GI tract.