Why do you want to go to the bathroom when you are nervous?

Nervousness in going to the toilet is a physiological reaction.

Because there is a fundamental internal relationship between physiology and psychology, many changes in physiological function are carried out under the control and command of psychological function. When people's psychology is in a state of excessive tension and anxiety, the function of autonomic nervous system will be disordered, which will cause the physiological reaction of wanting to go to the toilet.

This physiological reaction is only a physiological reaction under the control of psychological function.