Rapid Gastric Emptying

Rapid gastric emptying, also called “dumping syndrome,” occurs when the small intestine fills too quickly. Foods and such, mostly undigested, pass through the stomach too rapidly and quick “dumping” then occurs.

Rapid gastric emptying encircles both “early” dumping and “late”dumping. Early dumping begins either during or right after a meal. Symptoms may include nausea, vomiting, bloating, cramping, diarrhea, dizziness, sometimes a shortness of breath, and often fatigue. Late dumping will happen anywhere from one to three hours following a meal, and these symptoms will commonly include hypoglycemia, weakness, sweating, and dizziness. It is not uncommon for patient to suffer from both early and late dumping -- which is termed “combined” dumping.

Dumping syndrome is often found in patients that have undergone certain types of stomach surgeries, those with diabetes mellitus, and those suffering from Zollinger-Ellison syndrome. Doctors diagnose dumping syndrome most commonly in patients that have undergone gastric surgery and present with the above mentioned symptoms, however, further testing is recommended to exclude any other conditions that have mirroring symptoms.

A gastric emptying study can be done to help with diagnosis. According to the Gastric Emptying Study Center, a gastric emptying study is a procedure that is done by nuclear medicine physicians using radioactive chemicals that measures the speed with which food empties from the stomach and enters the small intestine. Gastric emptying studies are used for testing patients who are having symptoms due to either slow or rapid emptying of the stomach.

For a gastric emptying study, a patient eats a meal in which a solid component of the meal (for example, scrambled egg), a liquid component of the meal (for example, water), or both, are mixed with a small amount of radioactive material. A scanner is placed over the patient’s stomach to monitor the amount of radioactivity in the stomach for several hours after the test meal is eaten. As the radioactively labeled food empties from the stomach, the amount of radioactivity in the stomach decreases. The rate at which the radioactivity leaves the stomach reflects the rate at which food is emptying from the stomach.

Medications that affect emptying of the stomach should be withheld for 48 to 72 hours before performing an emptying study. Abnormally high blood glucose (sugar) levels also can slow emptying of the stomach. Therefore, it is important to control blood glucose levels to near normal levels before performing emptying studies in patients with diabetes who are prone to develop high blood glucose levels.

Treatment for rapid gastric emptying is most commonly changes in eating habits and certain medications. For example, eating several small meals a day that are low in carbohydrates is recommended, as is only drinking liquids between meals and not with them. People with more severe cases take medicine to slow their digestive process. Some medications such as narcotic pain relievers and anticholinergic medications can delay emptying of the stomach. One should also be aware that other medications such as metoclopramide (Reglan) and erythromycin can cause rapid emptying of the stomach.

A person’s gastric emptying rate will also directly affect a person’s ability to participate in effective oral drug therapies. This is because of how quickly or slowly the patient may be able to absorb an oral therapeutic into the blood stream. It was because of this that Xanthus Life Sciences developed a method for measuring an individual’s gastric emptying rate.

The Xanthus technology detects the levels of a non-radio-labeled form of CO2 in a breath sample as a carbon-containing substrate is digested by measuring the rate at which the labeled nutrients are absorbed in the small intestine and metabolized into labeled CO2. Xanthus’ approach is designed to allow the mechanical aspects of drug absorption to be evaluated independently from other contributing factors to variability among individuals in drug exposure from oral doses. Therefore, the company believes that the technology may provide a phenotypic basis for developing and adjusting dosing regimens.

“The normal phenotype of emptying times can vary between 45 and 130 minutes without evidence of pathology, and may be a critical determining factor in drug absorption and subsequent exposure if too fast or too slow,” Alfred M. Ajami, chief scientific officer at Xanthus, said in a company press release. “Using this technology to measure gastric emptying may help drug developers identify patients whose gastric motility is either too fast or too slow from the norm for maximally effective oral therapy. This ability to measure gastric emptying would therefore enable smaller, more efficient clinical trials with reduced potential for error and risk. And importantly, the technology is non-invasive and does not involve radioactive probes or radiological procedures.”

Delayed drug absorption due to altered gastric emptying can result in therapeutic failure, especially if the drug has a short biological half-life, according to the company.

In extreme cases of rapid gastric emptying, surgery may be the recommended treatment. Whatever the case, management of patients suffering from rapid gastric emptying requires an understanding of the pathophysiology, clinical tests, and new treatment options.

2. Xanthus Life Sciences. “Xanthus Receives Patent on Technology to Measure Gastric Emptying.” Aug. 3, 2004.

3. Hagerstown, MD. “Disorders of Gastric Emptying.” Textbook of Gastroenterology. 4th ed. [2-volume set]. Lippincott Williams and Wilkins. 2003. p. 1292-1320.

4. Wrong Diagnosis.com. “Symptoms of Rapid gastric emptying.”
www.wrongdiagnosis.com/r/rapid_gastric_emptying/symptoms.htm#symptom_list.

5. Lee, Dennis and Marks, Jay W. “Gastric Emptying Study.”
www.medicinenet.com/gastric_emptying_study/page2.htm.