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.
While the loss of consciousness with vasovagal syncope can be quite sudden, more typically it is preceded by a few seconds or a few minutes of warning symptoms. These warning symptoms often include lightheadedness, ringing in the ears, visual disturbances, sweating and/or nausea.