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Gastroparesis Institute of USC

Gastroparesis Institute team:  John C. Lipham, MD

About Gastroparesis

Gastroparesis is a stomach disorder in which food moves through the stomach more slowly than normal. In a healthy digestive system, strong muscular contractions move food from the stomach through the digestive tract. With gastroparesis, however, the stomach muscles work poorly (or not at all), thus preventing the stomach from emptying properly.

The impact of gastroparesis on physical well-being can be devastating. It can cause chronic nausea and vomiting and lead to malnutrition and inadequate blood sugar levels. Living with gastroparesis also affects emotional well-being—the constant discomfort of chronic nausea and vomiting can have an
impact on school and work performance, family and personal relationships, and social activities.

The number of people with gastroparesis is unknown. There is no cure, but there are therapies that improve symptoms and offer hope for a better quality of life.

How the Stomach WorksHow the Stomach Works

The stomach’s job involves storage of food, mixing food with stomach secretions, grinding food into small particles, and moving these particles into the small intestine. Solids and liquids empty at different rates, and emptying is controlled by muscle contractions in different regions of the stomach. All of these processes should occur at a rate that makes digestion easy and efficient. If stomach muscle contractions stop working properly, the result can be “delayed gastric emptying,” where undigested food and fluids sit in the stomach and cause uncomfortable symptoms such as chronic nausea and vomiting.

Normal Stomach Emptying

Gastric emptying involves storage, the mixing of food with stomach secretions, the grinding of food into small particles, and the movement of ground particles into the small intestine at a rate that optimizes digestion. Solids and liquids empty at different rates, and emptying is controlled by muscle contractions in different regions of the stomach.

Liquid emptying is rapid and is controlled by the upper portion of the stomach (fundus). Emptying of digestible solids is characterized by a lag during which stored food moves from the upper to the lower stomach (antrum), where it is ground into small particles by powerful circular contractions. The lag phase is followed by an emptying phase during which the ground particles move from the lower stomach into the duodenum and small intestine.

Stomach muscle contractions are controlled by electrical signals generated at the junction of the upper one-third and lower twothirds of the stomach. The major factor controlling this electrical activity is feedback from neural receptors in the small intestine. Studies have shown that even when there is no apparent neurological damage, many cases of gastroparesis result from a deficiency in neural feedback.

Impact of Gastroparesis on Patients

Gastroparesis is a debilitating condition because of chronic nausea and vomiting and the severity of abdominal discomfort. If vomiting episodes cannot be controlled through dietary modification or medication, then dehydration, significant weight loss, and poor nutrition are inevitable.

In chronic cases, patients are forced to withdraw from school, work, and social activity because they lack the physical energy needed to perform normal daily activities. Patients may become too weak to get out of bed and may require hospitalization to restore fluids and provide nutritional support.

Nutritional support via a surgically inserted feeding tube or indwelling intravenous catheter may be necessary if sufficient caloric intake cannot be maintained. These methods of nourishment carry the risk of infection in an already compromised individual.


Next: Causes and Symptoms of Gastroparesis

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USC Gastroparesis Institute
1510 San Pablo St., Suite 514
Los Angeles, CA 90033

Phone: (323) 442-6868

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