The causes of duodenal obstruction include tissue damage, growths, congenital defects or a foreign object blockage of the upper digestive tract. In infants and small children, a duodenal obstruction is often caused by some type of congenital defect which results in malformation of one or more areas of the upper digestive tract. A duodenal obstruction in adults is most often caused by a foreign object becoming lodged in the passage, or by a narrowing of the passageway due to scar tissue formation, tumor growth, or infection.
The first and shortest part of the small intestine is the duodenum, which is followed by the jejunum, and lastly by the ileum. The duodenum is also known as the anterior or proximal intestine and together with the upper jejunum is responsible for most of the digestive tract's iron absorption.
The stomach, pancreas, and gall bladder all empty into the duodenum, which continues the digestive process started in the stomach. The pancreas is an endocrine gland that secretes important hormones like insulin, but it is also a digestive organ that produces digestive enzymes which empty into the duodenum. The gall bladder helps with the digestion of fats and acts as a storage area for extra bile produced by the liver. It releases its contents into the duodenum when undigested fats are detected.
Duodenal obstruction prevents the stomach from passing foodstuffs into the duodenum, disrupting the digestive process and blocking the gall bladder and pancreas from adding their digestive secretions. The degree of duodenal obstruction can range from a partial to a complete blockage. The resulting symptoms for both infants and adults include nausea, abdominal pain or discomfort, abdominal distension, and green vomit caused by the build-up of gall bladder secretions.
Some of the most common causes of duodenal obstruction in children and babies include an underdeveloped duodenal lumen, also known as the duodenal channel, which is called duodenal hypoplasia; a narrowed duodenal lumen, which is called duodenal stenosis; and a malformed duodenal lumen, which is called duodenal atresia. Malrotation or coiling of the duodenum is also a common cause of obstruction. Occasionally duodenal malrotation is accompanied by volvulus, which is when the duodenum twists around itself.
In adults, a blockage can occur from the ingestion of a foreign object which becomes wedged in or near the duodenum, or by the lodging of an internally sourced foreign object, such as a gallstone. Inflammation or infection caused by conditions like diverticulitis and Crohn's disease are common causes of duodenal obstruction in adults, but are much less common in children. Tumors, which can be benign or malignant, can cause a blockage. Scar tissue accumulation caused by peptic ulcers was once a common cause of obstruction, but improvement of the medical treatment of ulcers has greatly reduced such complications. In most cases, the medical treatment for a duodenal obstruction includes surgical intervention.
