As with any hollow organ, a blockage may occur in the stomach which can affect its normal functioning. These blockages may be due to growths, thickening of the inlet or outlet, or pressure from outside the stomach which causes a narrowing. Blockages can lead to complications like dehydration and nutritional deficiencies. Some causes like cancerous growths may also be life threatening.
Location of the Blockage
The stomach is a relatively large organ with a narrow inlet and outlet. It is usually the inlet or outlet where an obstruction may arise. The inlet region is known as the cardia and the outlet is the pylorus. Obstructions are usually partial (incomplete) meaning that there is still some space for food and fluids to pass through.
Most of the time the obstruction affects the stomach outlet and this is collectively known as gastric outlet obstruction. This area is known as the pylorus and is the end portion of the stomach which then continues into the duodenum of the small intestine.
Most of the stomach lies in the upper left quadrant of the abdomen and the pylorus is located approximately in the upper middle region of the abdomen. Sometimes a mass or narrowing of the duodenum can impede the exit of stomach contents. However, gastric outlet obstruction usually involves pathology in the pylorus of the stomach.
The thick band of muscles in the pylorus controls the outflow of stomach contents. It is referred to as the pylorus sphincter and is a valve that opens and narrows as is required. It ensures that food in the stomach is sufficiently digested, albeit partially, to then exit the stomach and continue through to the small intestine.
It is also important to note that the muscles in the stomach wall are also responsible for movement of food through the stomach. If these muscles become weak or paralyzed then food may be backed up in the stomach. As a result it leads to a pseudo-obstruction, which means a false obstruction.
Signs and Symptoms
A blockage in the stomach usually presents with non-specific symptoms. Nausea is the most prominent symptoms and is usually accompanied by vomiting that tends to arise a short while after eating. Other symptoms include bloating (sensation of fullness) and feeling full after a few bites of a meal (early satiety). Sometimes these symptoms of a stomach blockage are described as indigestion, and often ignored until other more serious symptoms arise.
Over time other symptoms like unintentional weight loss arise and is usually related to ongoing diminished appetite. This in turn may be accompanied by the signs of dehydration and nutritional deficiencies. Abdominal pain does not occur with every case of a stomach blockage. It is usually seen with conditions like peptic ulcers and stomach or pancreatic cancer. This is often reported as an upper middle abdominal pain (epigastric pain).
Read more on epigastric pain.
Causes of Stomach Blockage
There are many possible causes of a blockage in the stomach and some of these conditions are common. However, these common stomach conditions do not always lead to an obstruction. Instead gastric outlet obstruction may occur as an uncommon complication. Some of the other causes can also be serious apart from the blockage that it causes and may even be potentially fatal.
Read more on gastric outlet obstruction.
Peptic ulcer disease is where an open sore forms in the stomach or duodenum. It is a common condition and may be associated with gastritis (stomach wall inflammation). These ulcers are mainly due to Helicobacter pylori (H.pylori) bacteria or the excessive use of NSAIDs.
It causes localized inflammation which can lead to swelling of the stomach wall tissue. This can cause a blockage in acute peptic ulcers. Over time this persistent inflammation can lead to scarring of the stomach wall which causes the narrowing. This is seen in chronic peptic uclers.
The most common cause of a stomach blockage, specifically gastric outlet obstruction, is pyloric stenosis. Pyloric refers to the end part of the stomach known as the pylorus. Stenosis is a medical term for narrowing. It is develops in infants and is more common among boys than girls.
Pyloric stenosis is the gradual enlargement (hypertrophy) of the smooth muscles that makes up the pyloric sphincter. The exact cause of pyloric stenosis is unclear. It has been linked to genetic factors, bottle-feeding, use of certain antibiotics during pregnancy and during the infant years, as well as smoking during pregnancy.
Stones and Objects
Another one of the more common causes of gastric outlet obstruction is a blockage due to a gallstone. Large stones may cause obstructions of the bile duct or even within the digestive tract. Gallstones can become impacted in the duodenum or pylorus of the stomach. This is known as Bouveret syndrome.
Any substance or object that is ingested can become impacted in the stomach outlet thereby causing a blockage. This may include foreign bodies, larger pieces of undigested food, hair and certain drugs. These objects are referred to as bezoars when it causes a blockage in the stomach.
There are a number of benign (non-cancerous) growths that may responsible for gastric outlet obstruction. Some of these growths have the potential to become cancerous and need to be constantly monitored. These growths include:
- Stomach polyps which are abnormal growths that protrude from the stomach wall. These growths may be linked to chronic gastritis and long term use of drugs like proton pump inhibitors (PPIs).
- Duodenal webs are membranes with holes that form inside the stomach and usually are present from the time of birth.
- Pseudocysts are pockets filled with digestive enzymes and larger cysts can cause an obstruction in the pylorus of the stomach.
Malignant growths (cancerous tumors) are another possible and serious cause of gastric outlet obstruction. The most common type of cancer that may cause a stomach blockage is pancreatic cancer. Other forms of cancer may also be responsible including stomach cancer, bile duct cancer and cancers from other sites which spread to the stomach or duodenum (metastatic carcinomas).