Gastroparesis

What is Gastroparesis?

Gastroparesis literally means weakness or paralysis of the stomach. The lower portion of the stomach, or antrum which grinds solid food, contracts poorly, or not at all. As a result of this condition, the stomach becomes sluggish, and digests solid food very slowly.

Symptoms

Symptoms of gastroparesis are a result of slow gastric emptying. These include bloating, or a prolonged sensation of fullness after eating, nausea and vomiting, loss of appetite, and weight loss. A secondary effect of gastroparesis is excessive acid secretion. Filling the stomach "turns on" acid production. As the stomach digests the food and empties it into the intestine, acid production normally slows to a low basal, or resting, level. If the stomach does not empty, then acid production never slows down as it should. This leads to symptoms of indigestion, heartburn, regurgitation, and abdominal pain. These symptoms suggest the presence of an ulcer. Many patients with gastroparesis are initially diagnosed as having peptic ulcer disease, but usually fail to respond completely to treatment.

What causes it?

Gastroparesis may be a primary or secondary problem. Ulcers and tumors may cause swelling and a blockage which will not allow food to pass out of the stomach. Vomiting which occurs with food poisoning or intestinal flu may be a result of delayed gastric emptying. Helicobacter infection and various drugs can also cause delayed emptying. Hypothyroidism may also delay gastric emptying.

Gastroscopy is necessary in most cases to identify obstruction and other potential problems, and to diagnose complications such as esophagitis. Diabetes is the most commonly identified disease associated with gastroparesis, but in most patients there is no identifiable cause.

In many cases, nausea, vomiting and other symptoms of gastroparesis may vary in severity for no apparent reason. The response to medical treatment is also quite variable. This may make treatment difficult at times.

Diagnosis

Gastroparesis is diagnosed using a gastric emptying study. The patient is given a small meal containing a small amount of radioactive tracer. A gamma camera is placed over the stomach to measure the rate at which the stomach digests and empties the food. If the stomach is emptying slowly, Reglan can be given to see whether it speeds emptying. This information is sometimes helpful, as not all patients respond to Reglan. Other more complicated tests such as gastroduodenal motility studies and electrogastrography are being performed in research centers. These tests have helped us to better understand this disease, but are not required in the management of most patients.

Treatment

Reglan (metoclopramide) was the first drug released for treatment of gastroparesis. Reglan increases the muscular contraction of the stomach and speeds gastric emptying. It also strengthens the valve muscle at the lower end of the esophagus to reduce regurgitation and heartburn. The drug also has a direct effect on the brain to reduce nausea and vomiting. About ten percent of patients have side effects which require stopping the drug. Common side effects include drowsiness, anxiety or shakiness, muscle tremors or spasm, diarrhea, urinary frequency, and breast swelling or pain.
The usual dose of Reglan is 5 to 10 mg. four time a day, taken 30 minutes before each meal and at bedtime.

Other Drugs

Erythromycin is an antibiotic which improves gastric emptying by simulating the effect of a natural gut hormone called motilin. It is most effective if given intravenously. We have treated a number of patients with liquid erythromycin suspension given orally with variable results. Research is being done to develop similar compounds which can be used to treat gastroparesis

Cisapride (Propulsid) is no longer available for treatment of gastroparesis. It was withdrawn from the market because of reports of sudden cardiac deaths.

Drugs to reduce acid secretion may also alleviate some of the symptoms of gastroparesis. When the stomach remains full, acid is produced almost continuously. Fluid is also secreted into the stomach along with the acid and may contribute to fullness, bloating and vomiting. Tagamet, Zantac and other H2RAs (Histamine receptor antagonists) are usually not potent enough to turn off the acid in this condition. Most patients require a PPI (proton pump inhibitor) such as Prilosec, Prevacid, Aciphex, or Protonix, sometimes in rather high doses.

Antiemetics (drugs to relieve nausea and vomiting) such as Phenergan, Compazine and Tigan may also be useful in controlling the nausea and vomiting associated with this disorder. They are most readily absorbed when given as a liquid. Suppositories may be required to control vomiting. Because of potential side effects, these drugs should not be given for long periods of time unless absolutely necessary.

Diet

Diet can be very important in the management of gastroparesis. Even while taking medication, some patients are unable to tolerate solid foods. This is because the stomach is unable to grind the food into particles small enough to pass into the intestine. Liquids are emptied more passively and do not require grinding. A liquid diet is often necessary, at least temporarily, in some patients with gastroparesis. Fatty foods can also cause worsening of nausea, vomiting and abdominal pain. This occurs because fats slow gastric emptying and delay digestion. A low fat diet is beneficial, at least for relief of symptoms. Maintaining a balanced, complete diet is often difficult, and may require extra vitamins and other nutritional supplements.

A few patients will require placement of a feeding tube into the intestine in order to provide nutritional support. Occasionally, intravenous feedings (hyperalimentation) may be necessary. This is generally a temporary but life saving measure.