Gastroparesis

To understand gastroparesis, you first must understand how the stomach functions. The stomach has two parts. The upper portion is called the fundus which is where swallowed food and liquid collect. The lower portion is called the antrum. This is the stomach grinder. It is where food is churned back and forth until it is broken into small fragments and then squirted out into the duodenum, the first part of the small intestine.

It may be a surprise to think of the stomach as being similar to the heart, yet this is really true. Both have an area within them called the pacemaker. This is where an electrical wave originates and then sweeps across the organ. The electrical wave causes the muscles in the heart and stomach to contract. In the stomach, the pacemaker is in the upper outer portion. The wave sweeps down across the antrum causing it to contract, grind up food, and expel small amounts. The normal rate of contraction is about three times a minute, much slower than the heart, but quite adequate for the job.

This condition occurs when the rate of the electrical wave slows and the stomach contracts less frequently. Now the food just lays in the stomach relying on acid and digestive enzymes to break down the food and on gravity to empty the stomach. There are a number of causes for this condition:

• Diabetes is the most common known cause. Adrenal and thyroid gland problems can also a cause although these are infrequent
• Scars from ulcers and tumors can block the outlet of the stomach and mimic gastroparesis
• Certain drugs weaken the stomach (Cardizem, Procardia, other calcium blockers, L-dopa, hyoscyamine, Bentyl, Levsin, narcotics)
• Previous stomach surgery, especially for ulcers
• Anorexia and bulemia
• Neurologic or brain disorders such as Parkinson’s disease or brain injuries
• Disorders such as lupus, scleroderma, and poor blood supply to the stomach
• Idiopathic which means the cause is not known. In 40% of instances, this is the case

It should be noted that not all of these disorders affect the pacemaker of the stomach, Some disorders weaken the stomach muscle itself so it can’t respond to the pacemaker. In either case, the result is the same, gastroparesis.

The usual symptoms of gastroparesis are a feeling of fullness after only a few bites of food, bloating—especially after eating, excessive belching, and nausea. At times there will be a vague, nagging ache in the upper abdomen but usually the pain is not sharp or crampy as might occur with ulcers or a gallbladder attack. There may be vomiting or regurgitation. Medications to reduce or eliminate stomach acid usually don’t help much. When gastroparesis is severe, there may be frequent heartburn and regurgitation of stomach juices into the mouth.

The diagnosis of gastroparesis starts with the medical history where the physician may suspect the diagnosis based on the symptoms. In severe cases, the physical exam and blood tests may show evidence for malnutrition, but usually the exam is normal.

An upper GI barium x-ray measures how liquid barium leaves the stomach. Often this exam is normal.

Upper endoscopy is a visual exam of the stomach using a lighted flexible tube. Mild sedation is usually given for this procedure.

This exam should always be done to be certain there is not a blockage in the stomach.

A gastric or stomach emptying test is presently the best method of making the diagnosis. In this test, a food, such as scrambled eggs, is labeled with a marker which can be seen by a scanner. Following ingestion, the scanner tracks the time it takes for the food to leave the stomach. In general, half the stomach contents should leave within 90 minutes.

A final test, which is not available everywhere, is the electrogastrogram (EGG). This test, like the EKG on the heart, measures the electrical waves that normally sweep over the stomach and precede each contraction.

First, if there is an underlying disorder, it needs to be treated effectively. Examples are good blood sugar control in the diabetic patient or thyroid medicine for someone with an underactive thyroid.

Second, there may be a need to address diet and nutrition. When gastroparesis is mild, there are usually few food problems. However, if there is marked delay in stomach emptying, then attention to the diet is necessary. Fats, including vegetable oils, normally cause delay in emptying of the stomach, so foods that are high in fat need to be avoided. High fiber foods such as broccoli and cabbage tend to stay in the stomach, so these foods should be restricted when symptoms are severe. Liquids always leave the stomach faster than solid food so liquid type foods such as low-fat milkshakes should be used. Finally, frequent small feedings, 4-6 times a day, are usually more effective than the normal but larger meals, 2 or 3 times a day. A registered dietitian can be very helpful in providing advice in severe cases.

The third treatment is medications.