If you have been experiencing vomiting after eating food, you may have gastric outlet obstruction (GOO).
In this post, we’ll discuss the following:
- What GOO is
- The symptoms of GOO
- The causes of GOO
- How GOO is diagnosed
- How GOO is treated
Let’s begin!.
What is gastric outlet obstruction?
Gastric outlet obstruction is a condition characterized by a blockage at the lower end of the stomach, which delays gastric emptying.
This blockage is usually caused by a cancerous mass, but you also have gastric outlet obstruction secondary to non-cancerous causes like a helicobacter pylori infection, volvulus, foreign bodies, and strictures.
H.pylori is a common infection worldwide, and it is the most common cause of peptic ulcer disease. This is where patients develop ulcers near the end of the stomach, which can lead to scarring and benign gastric outlet obstruction.
On the other hand, volvulus occurs when the gut twists around itself for one reason or another. This can also block the lower end of the stomach, leading to GOO.
What are gastric outlet obstruction (GOO) symptoms?
The most common symptom of GOO is post-prandial vomiting. This vomiting occurs 1-2 hours after a meal and contains foodstuffs because of delayed gastric emptying.
Other symptoms can include:
- Weight loss
- Abdominal pain
- Dilated abdomen
- Feeling full after eating just a little
- Succussion splash, which is a splashing sound that is heard when you shake the patient’s belly. This sound is usually found in healthy individuals immediately after eating a meal. However, if it’s heard more than 3 hours after a meal, it indicates GOO.
Some patients with GOO might also have symptoms related to electrolyte imbalance. That’s because when you vomit constantly, you lose potassium from the body. This can result in symptoms like:
- Nausea
- Fatigue
- Palpitations
- Muscle weakness
- Low blood pressure
It’s important to note that vomiting after eating food can also occur in other conditions. For example, if you vomit immediately after a meal, you may have a problem with the esophagus (and not the stomach).
Similarly, if the color of your vomit is green, then you may have duodenal obstruction, an obstruction in the small intestine instead of the stomach.
This is why it’s important to present an accurate account of your symptoms to your doctor so they rule out other conditions that mimic GOO, such as pyloric stenosis.
What is the most common cause of gastric outlet obstruction in adults?
The most common cause of gastric outlet obstruction in adults is cancer. This is called malignant gastric outlet obstruction, and it can be both intrinsic and extrinsic to the stomach.
Intrinsic obstruction is caused by cancers of the stomach and duodenum (the small intestine), while extrinsic compression can occur from pancreatic cancer, lymphoma, or biliary tract cancer.
Interestingly, the most common cause of GOO was H.pylori before it was displaced by cancer. This happened because we can now prevent, diagnose, and treat H.pylori infections very well, which has reduced the number of patients that get GOO because of it.
Which diagnostic test is best suited to help identify gastric outlet obstruction?
The best test to diagnose gastric outlet obstruction is an esophagogastroduodenoscopy, which is also called an upper gastrointestinal endoscopy.
During an endoscopy, a doctor inserts a long, flexible tube with a camera attached to your mouth and down your gastrointestinal tract.
This helps them directly look at the obstruction. It also allows them to take a small piece of the obstructing tissue and send it to the lab for cancer testing. This procedure is called a biopsy, and it’s the only way to diagnose cancer, the most common cause of GOO.
How is gastric outlet obstruction diagnosed?
Gastric outlet obstruction is diagnosed by a combination of history, physical examination, and investigations.
During history taking, your healthcare provider will ask you questions about your symptoms. Next, they will conduct a physical exam, where they will listen for the succussion splash and look for any abdominal distention.
If they think your history and physical exam point towards GOO, they will ask you to undergo certain investigations to confirm the diagnosis. These include:
- Upper GI series, where you have to swallow a fluid. Next, the healthcare provider takes images of your gut, which is clearly visible due to the fluid you swallowed. This helps doctors identify the site and size of the obstruction.
- CT scan or MRI
- Upper gastrointestinal endoscopy, which is the confirmatory test as discussed above
- Lab investigations support the diagnosis by revealing low potassium and chloride levels.
How do you treat a gastric outlet obstruction?
Gastric outlet obstruction is treated with a combination of supportive care and definitive treatment.
Supportive care aims to keep the patient comfortable while the doctor determines the exact cause of their gastric outlet obstruction and plans treatment. It involves:
- Stopping all oral intake
- Passing a nasogastric tube, which starts at the nose and ends at the stomach. This can be used to decompress the stomach if the pressure is too high.
- Giving IV fluids and electrolytes
- Giving IV proton pump inhibitors reduces acid production and prevents further damage to the stomach’s lining.
- Drugs for relieving pain and vomiting
Once the patient has been stabilized through supportive care, the doctor then provides definitive treatment for GOO. This involves reliving the obstruction and treating its underlying cause.
For example, if the cause of GOO is peptic ulcer disease, treatment will involve acid-suppressing drugs and antibiotics against H.pylori (which is the main cause of peptic ulcer disease).
But at the same time, you might also have to undergo a surgical procedure to relieve the obstruction. This can include:
- Endoscopic stenting
- Endoscopic balloon dilation
- Gastrojejunostomy, where the surgeon bypasses the obstruction and creates a new connection between the stomach and the small intestine. This is a major operation, so it’s a good idea to read our post on leaving the hospital after a major surgery.
- Gastrectomy, where a part of the stomach is removed
- Radiation and chemotherapy in case of malignant obstruction
The exact procedure you get for gastric outlet obstruction depends on the cause of your obstruction and your overall health status.
Gastric outlet obstruction overview
Gastric outlet obstruction is a blockage that prevents food from passing into the small intestine. It can occur due to various causes, such as tumors, inflammation, or scarring. The most common symptom is nausea and vomiting after having meals.
If you suspect you may have GOO, your doctor will likely conduct various tests to diagnose the condition. These include an upper GI series, CT scan, MRI, and endoscopy.
Finally, treatment will involve supportive care and definitive treatment. Supportive care is aimed at making the patient more comfortable while they are being worked up, while definitive treatment is aimed at relieving the obstruction and treating its underlying cause.
Depending on the cause of the obstruction, definitive treatment could include stent placement, gastrojejunostomy, gastrectomy, radiation, and chemotherapy.
