Gastroparesis may sometimes be caused by damage to the vagus nerve, which is a nerve that controls the muscles in the stomach, according to Mayo Clinic. The direct cause of gastroparesis is not always evident, however. The damage to the vagus nerve can result from a surgical procedure on the stomach or small intestine, or diseases such as diabetes.
The vagus nerve is responsible for important digestive processes, including signaling the stomach muscles to move food from the stomach to the small intestine, notes Mayo Clinic. If the vagus nerve is not able to communicate properly, the food ends up staying in the stomach longer than is normal, leading to digestive issues.
Other factors that may interfere with the normal emptying of the stomach include abdominal or esophageal surgery or virus infections, states Mayo Clinic. Some narcotic pain medications or other medications may slow down the stomach's emptying process. Radiation therapy and other cancer treatments may also contribute to gastroparesis.
A connective tissue disease called scleroderma may cause the stomach not to empty properly, according to Mayo Clinic. Parkinson's disease, multiple sclerosis and other diseases associated with the nervous system may lead to gastroparesis as well. A low thyroid, or hypothyroidism, is another possible cause. Young women and middle-aged women have an increased risk of experiencing idiopathic gastroparesis.