my nephew, 40 years old, went to the hospital throwing up blood and bleeding rectally. they did a colon scope which showed a large hemroid, too big to remove except by surgery. then they did the upper scope into his stomach, it showed that most of his stomach had no blood flow, they thought because of a blockage like a clot but they did an ultrasound this morning and the vessels are clear and they have no answers for us. They said they have never seen this before, what could it be