Dracula II: Ascension (2003)

Father Uffizi hunts vampires. He travels the world to behead them with his bullwhip, but his ultimate goal is to find the first vampire, Dracula. Medical students, Liz Blaine and Luke are charged with autopsying the body. When they open the abdominal cavity, they find that the liver and other organs are white, suggesting to Luke that the person did not produce his own blood but got it elsewhere, i.e., a vampire.