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.
Several triggers can cause vasovagal syncope. To help reduce the risk of fainting, you can avoid some of these triggers such as: Standing for long periods. Excess heat. Intense emotion, such as fear. Intense pain. The sight of blood or a needle. Prolonged exertion. Dehydration. Skipping meals.