Electrogastrogram (EGG)

An electrogastrogram is similar to an electrocardiogram (EKG) of the heart. It is a recording of the electrical signals that travel through the muscles of the stomach and control the muscles' contraction.

An electrogastrogram is used when there is a suspicion that the muscles of the stomach or the nerves controlling those muscles are not working normally. Usually, this suspicion arises when there is a problem with recurrent nausea and vomiting, signs that the stomach is not emptying food normally. If the electrogastrogram is abnormal, it confirms that the problem probably is with the stomach's muscles or the nerves that control the muscles. The electrogastrogram can be considered an experimental procedure since its exact role in the diagnosis of diseases of the stomach has not been defined yet.

For an electrogastrogram, several electrodes are taped onto the abdomen over the stomach in the same manner as electrodes are placed on the chest for an electrocardiogram. The electrodes sense the electrical signals coming from the stomach's muscles, and the signals are recorded on a computer for analysis. Recordings are made both fasting and after a meal with the patient lying quietly. The study takes two or three hours.

In normal individuals, there is a regular electrical rhythm generated by the muscles of the stomach--just as in the heart--and the power (voltage) of the electrical current increases after the meal. In patients with abnormalities of the muscles or nerves of the stomach, the rhythm often is irregular or there is no post-meal increase in electrical power.

There are no side effects. The study is painless.

No, there are no alternatives to this study. Other studies, however, for example, antro-duodenal motility studies or gastric emptying studies may give additional information since the abnormal electrical activity of the stomach often results in abnormal muscular activity and reduced or delayed emptying of food from the stomach.