Gastroparesis

Gastroparesis, also called delayed gastric emptying, is a disorder in which the stomach takes too long to empty its contents. It often occurs in people with type 1 diabetes or type 2 diabetes.

Gastroparesis happens when nerves to the stomach are damaged or stop working. The vagus nerve controls the movement of food through the digestive tract. If the vagus nerve is damaged, the muscles of the stomach and intestines do not work normally, and the movement of food is slowed or stopped.

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. 

Symptoms and Complications

Signs and symptoms of gastroparesis are

• 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

These symptoms may be mild or severe, depending on the person.

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.

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.

• Upper endoscopy. After giving you a sedative, the doctor passes a long, thin tube called an endoscope through the mouth and gently guides it down 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 or pancreatitis as a source of the problem, you may have an ultrasound test, which uses harmless sound waves to outline and define the shape of the gallbladder and pancreas.
  

Causes

Gastroparesis is most often caused by

• diabetes
  
  
• postviral syndromes
  
  
• anorexia nervosa
  
  
• surgery on the stomach or vagus nerve
  
  
• medications, particularly anticholinergics and narcotics (drugs that slow contractions in the intestine)
  
  
• gastroesophageal reflux disease (rarely)
  
  
• smooth muscle disorders such as amyloidosis and scleroderma
  
  
• nervous system diseases, including abdominal migraine and Parkinson's disease
  
  
• metabolic disorders, including hypothyroidism

Reference:

National Digestive Diseases Information Clearinghouse, USA.