Changes

==Pathophysiology==

==Pathophysiology==

It is important to understand the pathophysiology of gastrointestinal obstructions in order to clinically assess the patient and formulate a treatment plan. Abnormalities of the equine [[Gastrointestinal Tract|gastrointestinal tract]] which prevent the progression of intestinal contents constitutes, an obstruction. Obstructions can be physical or functional and they can be broadly divided into simple obstructions, strangulating obstructions, and non-strangulating [[infarctions]].

It is important to understand the pathophysiology of gastrointestinal obstructions in order to clinically assess the patient and formulate a treatment plan. Abnormalities of the equine [[Gastrointestinal Tract|gastrointestinal tract]] which prevent the progression of intestinal contents, constitutes an obstruction. Obstructions can be physical or functional and they can be broadly divided into simple obstructions, strangulating obstructions, and non-strangulating [[infarctions]].

===Simple Obstruction===

===Simple Obstruction===

This is characterised by a physical obstruction of the intestine, which can be due to impacted food material, [[stricture]] formation, or foreign bodies.  The primary pathophysiological abnormality caused by this obstruction is related to the trapping of fluid within the intestine oral to the obstruction.  This is due to the large amount of fluid produced in the upper gastro-intestinal tract (around 125L daily), and the fact that this is primarily re-absorbed in parts of the intestine downstream from the obstruction.

This is characterised by a physical obstruction of the intestine with no initial vascular compromise to the affected bowel. A simple obstruction can be due to impacted food material, [[stricture]] formation, or foreign bodies.  The primary pathophysiological abnormality caused by this obstruction is related to the trapping of fluid within the intestine, oral to the obstruction.  This is due to the large amount of fluid produced in the upper gastro-intestinal tract (around 125L daily), and the fact that this fluid cannot reach the absorptive surfaces of the large intestine downstream from the obstruction. This fluid becomes sequestrated or can be lost by [[Nasogastric Reflux| nasogastric reflux]].  

The first problem with this degree of fluid loss from circulation is one of decreased plasma volume, leading to a reduced [[cardiac output]], and [[acid-base imbalance|acid-base disturbances]].

The first problem with this degree of fluid loss from circulation is one of decreased plasma volume, leading to a reduced [[cardiac output]], and [[acid-base imbalance|acid-base disturbances]].