Common types of UC include: 1  proctosigmoiditis, which affects the rectum and lower portion of the colon. 2  left-sided colitis, which affects the left side of the colon beginning at the rectum.  total colitis, which affects the entire large intestine.
Vasovagal syncope. Vasovagal syncope is a sudden loss of consciousness mediated by the vagus nerve. It occurs when the vagus nerve is overreactive to certain triggers, such as the sight of blood or extreme emotional distress, and causes a sudden drop in blood pressure.
As it turns out, fainting at the sight of blood may be a primitive reflex buried deep in our brain. Fainting, or vasovagal syncope, is a pretty uncomfortable experience. It's mediated by the vagus nerve, one of twelve cranial nerves, which has both motor and sensory components.