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.
The vagus nerve is involved in one of the most common causes of fainting, called vasovagal syncope. This is an overreaction of the body to certain stimuli, like the sight of blood, which involves the stimulation of the vagus nerve. This stimulation causes a drop in blood pressure and heart rate.Less blood flows to brain, resulting in loss of consciousness.his is an overreaction of the body to certain stimuli, like the sight of blood, which involves the stimulation of the vagus nerve. This stimulation causes a drop in blood pressure and heart rate. Less blood flows to brain, resulting in loss of consciousness.