WHAT IS GASTROPARESIS?
Gastroparesis is a condition in which food takes longer than usual to move from the stomach to the small intestine. There is typically no problem with digestion, which happens in the small intestine. Not all patients with slow movement from the stomach need specific treatment for gastroparesis.
In many instances, the delay in food movement out of the stomach is part of an IBS (irritable bowel syndrome)
-like disorder affecting the stomach, called functional dyspepsia. In other patients, there is a problem with how nerve signals are sent to the stomach muscles because of nerve damage (this can be seen in long standing diabetes
), or with the ability of the stomach muscle to respond to nerve signals (this can be seen in disorders like lupus, scleroderma, other connective tissue disorders). Medications can also have a significant impact on the speed of stomach emptying and cause gastroparesis, especially narcotic pain medications.
SYMPTOMS OF GASTROPARESIS
The symptoms of gastroparesis are the same as many other digestive disorders, so tests are necessary for diagnosis. Symptoms include:
- A feeling of fullness after eating just a few bites
- Heartburn or gastroesophageal reflux (GERD)
- Difficulty in controlling blood sugar levels in diabetes
- Weight loss and malnutrition
WHAT CAUSES GASTROPARESIS?
The cause of gastroparesis is not completely understood. Control of the stomach muscles through the the vagus nerve (a long nerve that extends between the brain and the abdomen) may be abnormal because of nerve damage from long standing diabetes (usually type 1), metabolic disorders, or diseases of the nervous system (e.g. Parkinson’s disease).
The vagus nerve is essential for movement of food through the esophagus, stomach and intestines. It signals the stomach muscles to contract and move food through the small intestine. If the nerve is malfunctioning, control of movement through the esophagus, stomach and intestines may be abnormal.
HOW IS GASTROPARESIS DIAGNOSED?
The gastroenterologist has several options to evaluate movement of food through the stomach:
- Measure the time the stomach takes to empty its contents: the patient swallows food containing a microscopic amount of radioactive material that will show up on a scanner. The scanner tracks the movement of the radioactive material through the stomach. This test is used frequently, but can be influenced by medications that slow movement out of the stomach.
- Endoscopy to see inside the stomach: This may show food remaining in the stomach in a patient who has not eaten for 6 or more hours, or after an overnight fast. An endoscopy is also important in looking at the outlet from the stomach to the intestines (pylorus) to make sure this is not narrowed. A narrowed part of the intestines (pyloric stenosis) can cause symptoms exactly similar to gastroparesis.
- Gastric manometry: the doctor passes a thin tube down the patient’s throat into the stomach and first part of the small intestine. Sensors inside the tube detects pressure changes within the stomach and small intestine that help determine if the stomach muscles are performing normally. This test is not performed very often in patients, but it a valuable research tool.
- Barium upper gastrointestinal series: the patient swallows a semi-liquid material called barium (a metallic, chalky liquid) that will coat the inside of the stomach and small intestine. The radiologist will take x-rays of the digestive organs, which appear on the x-ray due to the barium coating.
- Breath test: breath samples are taken after the patient eats food containing a small amount of isotope, in order to measure how much carbon dioxide containing the isotope is breathed out and determine how quickly the patient’s stomach is emptying.
Currently, there is no complete cure available for gastroparesis. Management of symptoms is possible, through diet changes or medication.
The gastroenterologist may refer the patient to a dietitian. A dietitian can recommend certain foods that move through the stomach easily, and contain nutrients that gastroparesis patients might become deficient in. Drinking more fluids during meals may help move food along through the stomach and intestines, as well as easy exercise (e.g. walking) after a meal. Specific vitamins may be prescribed in order to prevent deficiencies.
Medications that control nausea, vomiting and discomfort are used most often in treating gastroparesis symtpoms. There is no ideal medication to stimulate the stomach muscles that is uniformly effective and can safely be used long term. Within restrictions, some stimulatory medications may be appropriate for occasional patients.
In severe cases when the patient cannot move any food past the stomach or blood sugar cannot be maintained, the gastroenterologist may recommend that a feeding tube to be inserted into the small intestine to bypass the stomach. This is usually necessary when the patient develops weight loss from poor movement of food through the stomach.
Surgery is rarely necessary if the patient cannot move any food out of the stomach or if the patient is at severe risk of malnutrition. The surgery would remove part of the stomach, in order to create a direct connection between the esophagus and the intestine so that food can pass into the digestive tract.
Electrical stimulation is a recent development for treating some patients with gastroparesis. A stimulator (very different from pacemakers used for heart conditions) is surgically inserted into the abdomen and used to generate electrical pulses that are sent to the stomach muscles. This technique, however, does not improve speed of stomach emptying in most patients. It also does not control pain. Electrical stimulation appears to be most useful if the main symptom is vomiting. Therefore, this technique is not routinely utilized in gastroparesis.