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.
Long-term stomach cramping may be continuous or occur periodically and may be due to more serious conditions, such as colorectal cancer. In some cases, stomach cramps may be caused by serious conditions, such as food poisoning or colorectal cancer.