Vasopressin has three main effects: 1  Increasing the water permeability of distal convoluted tubule and collecting duct cells in the kidney, thus allowing water reabsorption and excretion of more concentrated urine, i.e., antidiuresis.
It can be caused by damage to the vagus nerve, which regulates the digestive system. A damaged vagus nerve prevents the muscles in the stomach and intestine from functioning, preventing food from moving through the digestive system properly. Often, the cause of gastroparesis is unknown.
In fact, some doctors have suggested that stressful situations trigger the stomach to produce more stomach acid, which causes symptoms that resemble heartburn. Some of the key causes of nervous stomach are: 1  Stomach ulcers and acid reflux disease (GERD) and irritable bowel syndrome (IBS).2  Changes in digestive enzymes. 3  Food allergies and the intolerance of specific foods. 4  Eating foods that spicy, oily, high in fat, as well as fast foods.n fact, some doctors have suggested that stressful situations trigger the stomach to produce more stomach acid, which causes symptoms that resemble heartburn. Some of the key causes of nervous stomach are: 1  Stomach ulcers and acid reflux disease (GERD) and irritable bowel syndrome (IBS).