Diabetes and Your Digestive Tract: Gastroparesis

Diabetes can damage the vagus nerve if blood glucose levels remain high over a long period of time. High blood glucose causes chemical changes in nerves and damages the blood vessels that carry oxygen and nutrients to the nerves.

Signs and Symptoms
These symptoms of Gastroparesis may be mild or severe, depending on the person.
Signs and symptoms of gastroparesis include:
> heartburn
> nausea
> vomiting of undigested food
> an early feeling of fullness when eating
> weight loss
> abdominal bloating
> erratic blood glucose levels
> lack of appetite
> gastroesophageal reflux
> spasms of the stomach wall

Complications of Gastroparesis
If food lingers too long in the stomach, it can cause problems like bacterial overgrowth from the fermentation of food. Also, 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.

Gastroparesis can make diabetes worse by adding to the difficulty of controlling blood glucose. 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.

Gastroparesis Diagnosis
The diagnosis of gastroparesis is confirmed through one or more of the following tests.

Barium x ray. After fasting for 12 hours, you will drink a thick liquid called barium, which coats the inside of the stomach, making it show up on the x ray. Normally, the stomach will be empty of all food after 12 hours of fasting. If the x ray shows food in the stomach, gastroparesis is likely. If the x ray shows an empty stomach but the doctor still suspects that you have delayed emptying, you may need to repeat the test another day. On any one day, a person with gastroparesis may digest a meal normally, giving a falsely normal test result. If you have diabetes, your doctor may have special instructions about fasting.

Barium beefsteak meal. You will eat a meal that contains barium, thus allowing the radiologist to watch your stomach as it digests the meal. The amount of time it takes for the barium meal to be digested and leave the stomach gives the doctor an idea of how well the stomach is working. This test can help detect emptying problems that do not show up on the liquid barium x ray. In fact, people who have diabetes-related gastroparesis often digest fluid normally, so the barium beefsteak meal can be more useful.

Radioisotope gastric-emptying scan. You will eat food that contains a radioisotope, a slightly radioactive substance that will show up on the scan. The dose of radiation from the radioisotope is small and not dangerous. After eating, you will lie under a machine that detects the radioisotope and shows an image of the food in the stomach and how quickly it leaves the stomach. Gastroparesis is diagnosed if more than half of the food remains in the stomach after 2 hours.

Gastric manometry. This test measures electrical and muscular activity in the stomach. The doctor passes a thin tube down the throat into the stomach. The tube contains a wire that takes measurements of the stomach's electrical and muscular activity as it digests liquids and solid food. The measurements show how the stomach is working and whether there is any delay in digestion.

Blood tests. The doctor may also order laboratory tests to check blood counts and to measure chemical and electrolyte levels.

To rule out causes of gastroparesis other than diabetes, the doctor may do an upper endoscopy or an ultrasound.

Treatment of Gastroparesis
The primary treatment goal for gastroparesis related to diabetes is to regain control of blood glucose levels. Treatments include insulin, oral medications, changes in what and when you eat, and, in severe cases, feeding tubes and intravenous feeding.

It is important to note that in most cases treatment does not cure gastroparesis—it is usually a chronic condition. Treatment helps you manage the condition so that you can be as healthy and comfortable as possible.

If you have gastroparesis, your food is being absorbed more slowly and at unpredictable times. To control blood glucose, you may need to do the following:

> take insulin more often
> take your insulin after you eat instead of before
> check your blood glucose levels frequently after you eat and administer insulin whenever necessary

Your doctor will give you specific instructions based on your particular needs.

Medication
Several drugs are used to treat gastroparesis. Your doctor may try different drugs or combinations of drugs to find the most effective treatment.

Metoclopramide (Reglan). This drug stimulates stomach muscle contractions to help empty food. It also helps reduce nausea and vomiting. Metoclopramide is taken 20 to 30 minutes before meals and at bedtime. Side effects of this drug are fatigue, sleepiness, and sometimes depression, anxiety, and problems with physical movement.

Erythromycin. This antibiotic also improves stomach emptying. It works by increasing the contractions that move food through the stomach. Side effects are nausea, vomiting, and abdominal cramps.

Domperidone. The Food and Drug Administration is reviewing domperidone, which has been used elsewhere in the world to treat gastroparesis. It is a promotility agent like metoclopramide. Domperidone also helps with nausea.

Other medications. 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 you have a bezoar, the doctor may use an endoscope to inject medication that will dissolve it.

Meal and Food Changes
Changing your eating habits can help control gastroparesis. Your doctor or dietitian will give you specific instructions, but you may be asked to eat six small meals a day instead of three large ones. If less food enters the stomach each time you eat, it may not become overly full. Or the doctor or dietitian may suggest that you try several liquid meals a day until your blood glucose levels are stable and the gastroparesis is corrected. Liquid meals provide all the nutrients found in solid foods, but can pass through the stomach more easily and quickly.

The doctor may also recommend that you avoid high-fat and high-fiber foods. Fat naturally slows digestion—a problem you do not need if you have gastroparesis—and fiber is difficult to digest. Some high-fiber foods like oranges and broccoli contain material that cannot be digested. Avoid these foods because the indigestible part will remain in the stomach too long and possibly form bezoars.

Feeding Tube
If other approaches do not work, you may need surgery to insert a feeding tube. The tube, called a jejunostomy tube, is inserted through the skin on your abdomen into the small intestine. The feeding tube allows you to put nutrients directly into the small intestine, bypassing the stomach altogether. You will receive special liquid food to use with the tube. A jejunostomy is particularly useful when gastroparesis prevents the nutrients and medication necessary to regulate blood glucose levels from reaching the bloodstream. By avoiding the source of the problem—the stomach—and putting nutrients and medication directly into the small intestine, you ensure that these products are digested and delivered to your bloodstream quickly. A jejunostomy tube can be temporary and is used only if necessary when gastroparesis is severe.

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, you attach a bag containing liquid nutrients or medication to the catheter. The fluid enters your bloodstream through the vein. Your doctor will tell you what type of liquid nutrition to use.

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

New Treatments
A gastric neurostimulator has been developed to assist people with gastroparesis. The battery-operated device is surgically implanted and emits mild electrical pulses that help control nausea and vomiting associated with gastroparesis. This option is available to people whose nausea and vomiting do not improve with medications.

The use of botulinum toxin has been shown to improve stomach emptying and the symptoms of gastroparesis by decreasing the prolonged contractions of the muscle between the stomach and the small intestine (pyloric sphincter). The toxin is injected into the pyloric sphincter.

Latest Research on Gastroparesis
NIDDK's Division of Digestive Diseases and Nutrition supports basic and clinical research into gastrointestinal motility disorders, including gastroparesis. Among other areas, researchers are studying whether experimental medications can relieve or reduce symptoms of gastroparesis, such as bloating, abdominal pain, nausea, and vomiting, or shorten the time needed by the stomach to empty its contents following a standard meal.