Medical Edge Newspaper Column

Comparing Two Gastric Disorders

Sept. 17, 2006
DEAR MAYO CLINIC:
Would you please explain the difference between gastroparesis and cyclic vomiting syndrome? -- Oklahoma City, Okla.

ANSWER:
There are several important differences between these disorders, and in fact the two are usually quite distinct.

Gastroparesis is characterized by the stomach's abnormally slow emptying. In cyclic vomiting syndrome (CVS), which involves well-defined episodes of vomiting, the opposite is true. With food being promptly and thoroughly thrown up, the stomach empties much too quickly.

The symptoms of gastroparesis include abdominal bloating, an early sense of fullness when eating, nausea and vomiting. CVS, by definition, is largely confined to the latter two.

CVS is basically a childhood disease -- though increasing numbers of adult cases have recently been documented -- while gastroparesis is usually seen in adults. A more important factor is medical history: Gastroparesis is commonly a byproduct of diabetes or a post-viral syndrome. While the cause of CVS is unknown, it is associated with migraine headaches in some patients or family members.

While both disorders are chronic, CVS episodes come and go, averaging some three or four attacks a year that may last several hours to several days each. In between, the patient is symptom-free. Gastroparesis, by contrast, is always there -- ever ready to assert itself after you eat.

Gastroparesis is reliably diagnosed, after making sure that the patient has no obvious blockages, with a gastric-emptying study that traces the emptying of material from the stomach. The test involves ingestion of a very small amount of radioactive material. But CVS has no confirmatory test. Doctors must review patients' symptoms and history, and systematically eliminate other possibilities.

A patient can ease the effects of gastroparesis through changes in dietary patterns. Numerous small meals taken over the course of the day, as opposed to the traditional three squares, can be a lot easier on the stomach -- as is separation of the solid from the liquid portion of the meal. Also, because fats can delay stomach-emptying and fiber tends to have a long residence time in the stomach, the gastroparesis patient's diet should be rich in low-fat and low-fiber foods. With CVS, dietary changes generally make little difference -- during attacks, the body pretty much ejects all comers.

Both diseases occasionally produce serious complications. CVS's intense and repeated vomiting can cause inordinate loss of water and salts, potentially leading to dehydration and electrolyte imbalance. And because gastroparesis slows the body's assimilation of nutrients, or may prompt the patient to drastically reduce food consumption, it carries the risk of excessive weight loss and malnourishment. Thus hospitalization -- to administer intravenous fluids, for example -- is sometimes indicated for both disorders.

In both diseases, available medications tend to be of modest benefit. For example, tricyclic antidepressants such as amitriptyline (Elavil), taken in low doses, have prevented episodes or reduced their frequency in some CVS patients, and with minimal side effects. Once an attack has begun, an antinausea drug like metoclopramide (Reglan) may help that symptom. This same drug has also been used to stimulate stomach-emptying for gastroparesis patients. Metoclopramide may produce major side effects, however, such as drowsiness and tremors.

More and better drugs for treating these conditions are needed. Meanwhile, the best way to manage them is to minimize the likelihood of episodes' occurrence through self-help measures such as getting plenty of rest, sleep and exercise; and avoiding potential triggering events such as overeating, eating before bedtime and motion-sickness-causing activities.

It should be noted that gastroparesis and CVS are relatively uncommon, whereas an acute attack of nausea and vomiting -- typically, from food poisoning or a viral infection -- is not at all uncommon. The average person typically endures such an interlude about once a year. The vast majority of these attacks are benign, short-lived and responsive to home or over-the-counter remedies.

-- Nicholas J. Talley, M.D., Ph.D., Gastroenterology, Mayo Clinic, Rochester, Minn.