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.
Unconsciousness is an obvious sign of fainting. Vasovagal syncope. Before fainting, the person may feel light-headed and shaky and experience blurred vision. The person may see spots in front of their eyes.. During this time, observers note paleness, dilated pupils, and sweating. While unconscious, the person may have low pulse rate (less than 60 beats/minute).