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.
Fainting may have a variety of causes. A simple episode, also called a vasovagal attack or neurally-mediated syncope, is the most common type of fainting spell. It is most common in children and young adults. A vasovagal attack happens because blood pressure drops, reducing circulation to the brain and causing loss of consciousness. If the syncope is prolonged, it can trigger a seizure. You may suffer from a simple fainting spell due to anxiety, fear, pain, intense emotional stress, hunger, or use of alcohol or drugs.