Vertebro-basilar arterial disease
Arterial disease in the upper spinal cord, or lower brain that causes syncope if there is a reduction in blood supply. This may occur with extending the neck or with use of medications to lower blood pressure. Other causes
There are other conditions which may cause or resemble syncope. Seizures and syncope can be difficult to differentiate. Both often present as sudden loss of consciousness and convulsive movements may be present or absent in either. Movements in syncope are typically brief and more irregular than seizures. Akinetic seizures can present with sudden loss of postural tone without associated tonic-clonic movements. Absence of a long post-ictal state is indicative of syncope rather than an akinetic seizure. Subarachnoid hemorrhage may result in syncope. Often this is in combination with sudden, severe headache. It may occur as a result of a ruptured aneurysm or head trauma.Heat syncope occurs when heat exposure causes decreased blood volume and peripheral vasodilatation. Position changes, especially during vigorous exercise in the heat, may lead to decreased blood flow to the brain. Closely related to other causes of syncope related to hypotension (low blood pressure) such as orthostatic syncope. Lactose intolerance can cause "a release of histamine, resulting in an extreme dilatation of the bloodvessels, resulting in a drop of blood pressure so that not enough blood reaches the brains, leading to dizziness, fainting, syncope, itching, hives, tingling or swelling of the lips, tongue, or throat; chest tightness, shortness of breath, or difficulty breathing, wheezing." (More in the article on 
 Lactose intolerance).
Prognosis
The prognosis for non-ischemic cases of SBO is good with mortality rates of 3–5%, while prognosis for SBO with ischemia is fair with mortality rates as high as 30%.Cases of SBO related to cancer are more complicated and require additional intervention to address the malignancy, recurrence, and metastasis, and thus are associated with poorer prognosis.All cases of abdominal surgical intervention are associated with increased risk of future small-bowel obstructions. Statistics from U.S. healthcare report 18.1% re-admittance rate within 30 days for patients who undergo SBO surgery. More than 90% of patients also form adhesions after major abdominal surgery. Common consequences of these adhesions include small-bowel obstruction, chronic abdominal pain, pelvic pain, and infertility. See also
Impaction (animals) – A blockage of the intestines in animals
Neonatal bowel obstruction – A blockage of the intestines in children

References
External links
Obstruction, Small Bowel at eMedicine
Obstruction, Large Bowel at eMedicine