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.
In other cases, it is caused by abnormal nervous system responses to activities such as urinating, having a bowel movement, coughing, or swallowing. In still other cases, no trigger can be identified. In most cases of vasovagal syncope, you have some warning that you are near fainting. These signs include dizziness, nausea, pale skin, tunnel-like vision, and profuse sweating. After the episode, symptoms may continue because of continued low blood pressure.