Gastroparesis

Gastroparesis is a disorder in which the stomach takes too long to empty its contents. Normally, the stomach contracts to move food down into the small intestine for digestion. The vagus nerve controls the movement of food from the stomach through the digestive tract. Gastroparesis occurs when the vagus nerve is damaged and the muscles of the stomach and intestines do not work normally. Food then moves slowly or stops moving through the digestive tract.



Other Names

 * Delayed gastric emptying

Signs and Symptoms
Common symptoms of gastroparesis include:


 * Heartburn
 * Pain in the upper abdomen
 * Nausea
 * Vomiting of undigested food (sometimes several hours after a meal)
 * Early feeling of fullness after only a few bites of food (early satiety)
 * Weight loss due to poor absorption of nutrients or low calorie intake
 * Abdominal bloating
 * High or low blood glucose levels
 * Lack of appetite
 * Gastroesophageal reflux disease (GERD)
 * Spasms in the stomach area

Eating solid foods, high-fiber foods such as raw fruits and vegetables, fatty foods, or drinks high in fat or carbonation may contribute to these symptoms.

The symptoms of gastroparesis may be mild or severe. Symptoms can happen frequently in some people and less often in others. Many people with gastroparesis experience a wide range of symptoms.

Causes
The most common cause of gastroparesis is diabetes. People with diabetes have high blood glucose (sugar), which in turn, causes chemical changes in nerves and damages the blood vessels that carry oxygen and nutrients to the nerves. Over time, high blood glucose can damage the vagus nerve. Some other causes of gastroparesis are:


 * Surgery on the stomach or vagus nerve
 * Viral infections
 * Anorexia nervosa or Bulimia
 * Medications, such as anticholinergics and narcotics, that slow contractions in the intestine
 * Gastroesophageal reflux disease (GERD)
 * Smooth muscle disorders, such as amyloidosis and scleroderma
 * Nervous system diseases, including abdominal migraine and Parkinson disease
 * Metabolic disorders, including hypothyroidism

Many people have what is called idiopathic gastroparesis, meaning the cause is unknown and cannot be found even after medical tests.

Exams and tests
After performing a full physical exam and getting a medical history, a doctor may order several blood tests to check blood counts and chemical and electrolyte levels. To rule out an obstruction or other conditions, the doctor may also perform the following tests:

Upper endoscopy
In this test, a sedative is given to make the patient drowsy. The doctor passes a long, thin tube called an endoscope through the mouth and gently guides it down the throat, also called the esophagus, into the stomach. Through the endoscope, the doctor can look at the lining of the stomach to check for any abnormalities.

Ultrasound
To rule out gallbladder disease and pancreatitis as sources of the problem, an abdominal ultrasound may be done. This test uses harmless sound waves to outline and define the shape of the gallbladder and pancreas.

Barium x ray
After fasting for 12 hours, the patient will drink a thick liquid called barium, which coats the stomach, making it show up on the x ray. If the patient has diabetes special instructions about fasting may be given. Normally, the stomach will be empty of all food after 12 hours of fasting. Gastroparesis is likely if the x ray shows food in the stomach. Because a person with gastroparesis can sometimes have normal emptying, the doctor may repeat the test another day if gastroparesis is suspected.

Once other causes have been ruled out, the doctor will perform one of the following gastric emptying tests to confirm a diagnosis of gastroparesis.

Gastric emptying scintigraphy
This test involves eating a bland meal, such as eggs or egg substitute, that contains a small amount of a radioactive substance, called radioisotope, that shows up on scans. The dose of radiation from the radioisotope is not dangerous. The scan measures the rate of gastric emptying at 1, 2, 3, and 4 hours. When more than 10 percent of the meal is still in the stomach at 4 hours, the diagnosis of gastroparesis is confirmed.

Breath test
After ingestion of a meal containing a small amount of isotope, breath samples are taken to measure the presence of the isotope in carbon dioxide, which is expelled when a person exhales. The results reveal how fast the stomach is emptying.

SmartPill
Approved by the U.S. Food and Drug Administration (FDA) in 2006, the SmartPill is a small device in capsule form that can be swallowed.The device then moves through the digestive tract and collects information about its progress that is sent to a cell phone-sized receiver worn around the waist or neck. When the capsule is passed from the body with the stool in a couple of days, the receiver is taken back to the doctor, who enters the information into a computer.

Treatment
Treatment of gastroparesis depends on the severity of the symptoms. In most cases, treatment does not cure gastroparesis, only manages the symptoms.

Medications
Several medications are used to treat gastroparesis. Different medications combinations may be tried in order to find the most effective treatment.


 * Metoclopramide stimulates stomach muscle contractions to help emptying. It also helps reduce nausea and vomiting. Metoclopramide is taken 20 to 30 minutes before meals and at bedtime. Side effects of this drug include fatigue, sleepiness, depression, anxiety, and problems with physical movement.
 * Erythromycin, an antibiotic, also improves stomach emptying. It works by increasing the contractions that move food through the stomach. Side effects include nausea, vomiting, and abdominal cramps.
 * Domperidone works like metoclopramide to improve stomach emptying and decrease nausea and vomiting. The FDA is reviewing domperidone, which has been used elsewhere in the world to treat gastroparesis. Use of the drug is restricted in the United States.
 * Other medications may be used to treat symptoms and problems related to gastroparesis. For example, an antiemetic can help with nausea and vomiting. Antibiotics will clear up a bacterial infection. If there is a bezoar in the stomach, the doctor may use an endoscope to inject medication into it to dissolve it. A bezoar is a ball of ingested material (usually hair or fiber) that cannot pass from the stomach to the intestines.

Feeding Tube
If a liquid or pureed diet does not work, surgery may be necessary in order to insert a feeding tube. The tube, called a jejunostomy, is inserted through the skin of the abdomen into the small intestine. The feeding tube bypasses the stomach and places nutrients and medication directly into the small intestine. These products are then digested and delivered to the bloodstream quickly. A special liquid food is given through the tube. The jejunostomy is used only when gastroparesis is severe or the tube is necessary to stabilize blood glucose levels in people with diabetes.

Parenteral Nutrition
Parenteral nutrition refers to delivering nutrients directly into the bloodstream, bypassing the digestive system. The doctor places a thin tube called a catheter in a chest vein, leaving an opening to it outside the skin. For feeding, a bag is attached containing liquid nutrients or medication to the catheter. The fluid enters the bloodstream through the vein.

This approach is an alternative to the jejunostomy tube and is usually a temporary method to get through a difficult period with gastroparesis. Parenteral nutrition is used only when gastroparesis is severe and is not helped by other methods.

Gastric Electrical Stimulation
A gastric neurostimulator is a surgically implanted battery-operated device that releases mild electrical pulses to help control nausea and vomiting associated with gastroparesis. This option is available to people whose nausea and vomiting do not improve with medications. Further studies will help determine who will benefit most from this procedure, which is available in a few centers across the United States.

Botulinum Toxin
The use of botulinum toxin has been associated with improvement in symptoms of gastroparesis in some patients; however, further research on this form of therapy is needed.

Holistic and alternative treatments
Changing one's eating habits can help control gastroparesis. A doctor or dietitian may prescribe six small meals a day instead of three large ones. If less food enters the stomach with each meal, it may not become overly full. In more severe cases, a liquid or pureed diet may be prescribed.

Fat naturally slows digestion and fiber is difficult to digest. These foods should be avoided with gastroparesis.

Risk Factors

 * Abdominal surgery
 * Taking medications that slow the rate of stomach emptying
 * Diabetes
 * Certain cancer medications
 * Medications that affect muscles or nerves

Delay of transit
If food lingers too long in the stomach, it can cause bacterial overgrowth from fermentation.

The food can harden into solid masses called bezoars that may cause nausea, vomiting, and obstruction in the stomach. Bezoars can be dangerous if they block the passage of food into the small intestine.

Diabetes and gastroparesis
Gastroparesis can make diabetes worse by making blood glucose control more difficult. When food that has been delayed in the stomach finally enters the small intestine and is absorbed, blood glucose levels rise. Since gastroparesis makes stomach emptying unpredictable, a person's blood glucose levels can be erratic and difficult to control.

The primary treatment goals for gastroparesis related to diabetes are to improve stomach emptying and regain control of blood glucose levels. Treatment includes dietary changes, insulin, oral medications, and, in severe cases, a feeding tube and parenteral nutrition.


 * Dietary changes such as more frequent, smaller meals may help to help restore blood glucose to more normal levels. In some cases, the doctor or dietitian may suggest eating several liquid or pureed meals a day until the blood glucose levels are stable and the symptoms improve. Liquid meals provide all the nutrients found in solid foods, but can pass through the stomach more easily and quickly.

If gastroparesis is present, food is being absorbed more slowly and at unpredictable times. To control blood glucose, it may be necessary to


 * take insulin more often or change the type of insulin used
 * take insulin after eating instead of before
 * check blood glucose levels frequently after eating and administer insulin whenever necessary

Clinical Trials
A list of ongoing clinical trials is available at gastroparesis trials

Recent discoveries

 * Patients were found to have delayed gastric emptying (gastroparesis) after the ingestion of caustic material, even in the absence of gastric symptoms.
 * The drug domperidone apprears to be an effective treatment for gastroparesis. Further studies are recommended.
 * The underlying pathophysiology of gastroparesis was evaluated. Some patients were noted to have significant changes in the gastric wall along with symptoms while others did not show the same changes on gastric biopsy. It is likely that gastroparesis is a multi-factoral disorder. The study authors recommend further studies to more accurately characterize the causes of gastroparesis.
 * Results from a recent study suggest that a predominant-symptom classification is a useful way to categorize patients with either vomiting-predominant or regurgitation-predominant gastroparesis. Separating patients into groups by predominant symptoms may help with their treatment. Patients with dyspepsia and delayed gastric emptying need further research.

Current research

 * The use of multi-channel electrical stimulation is evaluated as a treatment option for resistant gastroparesis.
 * Motilin is an experimental drug that increases the gastric emptying rate. Its efficacy (safety, side effects, and speed) in the treatment of gastroparesis is evaulated.