You are right! This experience is not surprising at all! For example, when you are about to go through significant moments such as examination, public speaking, or when you are waiting for your results, interview, etc. Your stomach will start making some strange sound, and you feel uneasy. It is in fact a reaction towards your nervousness.
According to American biologists, we have two brain systems that exist in our body. One is commonly known as our brain, while the other is the gastrointestinal tract in our stomach. They can sense one another and they are just like twins. As long as one of them does not feel good, the other will be affected similarly too.
Our stomach digestive system is composed of millions of neurons, and all these neurons construct our enteric nervous system, which communicate and interact with our brain through the sympathetic nervous system and parasympathetic nervous system. At the same time, our enteric nervous system can function by itself and think without submitting to the instructions of our brain. It can issue orders by itself and hence, it is known as the “second brain” of the human body.
Under normal circumstances, the muscles of our stomach will regulate itself, therefore we will not feel anything abnormal. However, when we become nervous, worried, stressed, excited or upset, our adrenal glands will secrete adrenaline and it causes a psychological fight-or-flight response in our physical body. At the same time, the enteric nervous system in our stomach and intestines (or gastrointestinal tract) will cause us to feel the emotion and feeling at that moment. The brain will process the emotion and react accordingly, which triggers a series of physical and chemical reactions in our body. For example, muscle tension and contraction in our stomach, the speed up of bowel movement. Because of these, you will suddenly have stomach pain and you just want to go toilet to poop immediately!
Hence, we can see that the function of our stomach is closely affected by our emotion. When we are in a bad mood, our stomach will suffer! This gives reasons to our poor appetite when we are feeling depressed, and our urge to visit the toilet when we become nervous.
Lastly, it is an art to master your emotion, to know how to adjust it and to relax. This will help to minimize the feeling of embarrassment as the result of running to the toilet during certain critical moments.