Pyloric stenosis or gastric outlet obstruction (GOO) refers to any condition that mechanically impairs the normal emptying of the stomach into the small intestine. It is caused by the muscles of the pyloric sphincter becoming enlarged and blocking the passage of food from the stomach to the small intestine. In children, the condition is commonly caused by pyloric stenosis which refers to a narrowing of the pylorus, the opening from the stomach into the small intestine. In adults, mechanical obstruction due to ulcers, tumors or gastric polyps are common causes of gastric outlet obstruction.

The condition occurs mostly in infants and newborns and is fairly uncommon. Studies have shown that infants with family members that have pyloric stenosis are at risk of inheriting the condition. Gastric outlet obstruction has also been shown to be more common in males than females. Another risk factor is the use of certain antibiotics. The use of antibiotics by the mother during pregnancy or in the first few weeks of life can greatly increase the risk of having the condition.

Gastric outlet obstruction in children

Pyloric stenosis is a common cause of GOO in children. It is generally detected before children are six months of age and more commonly affects boys than girls. Children whose parents have had pyloric stenosis are more likely to develop the condition; and it is believed that genetics plays a role in what causes the thickening of the pyloric wall.

Projectile vomiting is the most common initial symptom of pyloric stenosis. It may start from as early as three weeks of age, and may occur after some or all feeds. The infant is often still hungry after vomiting and may still want feeding. Other symptoms may include dehydration (depending on the severity of vomiting), failure to gain weight, belching and constant hunger. This condition needs to be treated surgically, for the health and wellbeing of the infant. If your child is experiencing any of these signs and symptoms, seek medical advice.

Gastric outlet obstruction in adults

The type of GOO in adults is often classified into two groups – either a benign (non cancerous) or malignant (cancerous) cause. The symptoms include nausea, vomiting, pain in the upper abdomen and a feeling of fullness in the upper abdomen. Regardless of the cause of GOO, initial treatment involves replenishment of fluids and electrolytes lost due to vomiting. Ongoing treatment involves correctly identifying the cause of the obstruction.

Gastric outlet obstruction can occur as a complication of peptic or duodenal ulcer disease in adults. If an ulcer develops just inside the duodenum (the first part of the small intestine) or at the pylorus, this can cause an obstruction. Benign gastric tumors (gastric polyps) are lesions that project above the surface of the walls of the stomach surface that are not cancerous. If located near the entry to the small intestine, they may cause gastric outlet obstruction. Certain cancers at advanced stages (including gastric, pancreatic and duodenal cancer) are commonly associated with the development of malignant tumors which obstruct the passage into the small intestine. Other possible causes include ingestion of corrosive substances, inflammatory conditions of the intestine (eg. Crohn’s disease) and the use of non-steroidal anti-inflammatory drugs.

Symptoms and Treatment

As mentioned above, a variety of symptoms can present themselves if pyloric stenosis is the cause. Stomach contractions, changes in bowel movements and dehydration are all possible. In severe cases, projective vomiting and constant feelings of hunger are key indicators that something is amiss. If the problem is allowed to progress, changes in weight will be apparent.

When vomiting occurs several things begin to happen. Vomiting depletes the amount of fluids in the body. This can cause dehydration and the loss of electrolytes. Potassium and chloride are electrolytes that are used by the body to regulate most of the body’s main functions, such as heartbeat and hormone secretion. Severe vomiting can also cause stomach irritation that could lead to ulcers and other problems within the digestive system. In rare cases, infants who exhibit symptoms of gastric outlet obstruction may also be jaundiced. Jaundice is a discoloring of the skin and eyes caused by the body’s inability to breakdown bilirubin. A yellow tint or pale orange discoloration is one of the main indicators of jaundice.

The treatment for gastric outlet obstruction is surgery. More often than not, the surgery is performed the same day as a diagnosis. This prevents any further damage to the stomach and small intestine. Because of the location of the surgery, the risk of infection is high. Antibiotics are prescribed to reduce the possibility of irritation and infection.