Why do you have to poop when you’re nervous?

The expressions “put in his pants” and “he shits seven colors of shit” both have to do with fright, fear and pooping. These stressful emotions are associated with the discharge of our feces for a reason. Many a burglar has left a dark brown message due to stressful circumstances. But stress at work can also cause you to have to go to the toilet more often. How exactly does that work?

Defecate

Under normal circumstances, the muscles in the digestive tract constantly tense and relax. The sandwich that you have just finished is worked forward by these grinding and propulsive movements. In the meantime, the digestive enzymes can do their job. After about twenty-four to forty-eight hours you have absorbed all the nutrients from the sandwich and you poop out the indigestible remains.

Types of stress

In daily life you can deal with different types of stress. First of all, there is “physical stress”, such as bleeding or infection. This type of stress is not considered in this article. You may also be dealing with “perceived stress”. For example, you may suffer from psychological stress because you have an exciting meeting at work. You may also have physical stress, for example because you are participating in an important handball match. All types of stress pose a threat to the body. In response to this threat, the body will take action.

Stress, the nervous system and hormones

A stress response starts in the brain. A stressful situation is signaled, after which a signal is sent to the amygdala. This is a brain region that is involved in emotions. Then the amygdala sends a signal to the hypothalamus; the control center of the brain. The hypothalamus communicates the perceived stress with the rest of the body through the autonomic nervous system.

Autonomous means that this is not under the influence of our will. It works automatically and it takes care of the maintenance of our body. The autonomic nervous system can be divided into the sympathetic nervous system (“the accelerator pedal”) and the parasympathetic nervous system (“the brake”). These two nervous systems have opposite effects on the organs.

When we experience acute stress (for example due to anger, fear or a stressful conversation), the hypothalamus pushes the accelerator. Our body is going to drive faster; it enters a state of heightened readiness. This is also known as the flight or fight (or fight or flight) response. Under the influence of acute stress, the sympathetic nervous system is therefore more stimulated than the parasympathetic nervous system.

After a few minutes to hours, the hypothalamus also activates the HPA system. This system represents the communication between the hypothalamus (a brain region), the pituitary gland (a brain region) and the adrenal cortex (a part of the kidneys that produces hormones).

Due to the activation of both the sympathetic nervous system and the HPA system, the body starts to produce hormones and neurotransmitters (signal substances). Examples include CRF (corticotropin-releasing factor), corticosteroids (adrenal cortex hormone) and catecholamines (adrenaline and noradrenaline; adrenal medulla hormones). As long as someone is in a stressful situation, these hormones keep the accelerator pressed.

Afterwards – when the danger has passed – a stimulation of the parasympathetic nervous system (“the brake”) ensures that the body calms down again.

Stress and pooping

Most is known about CRF. During acute stress, the amount of CRF in the brain rises. Especially in the areas of the brain that play a role in anxious feelings and digestion. The brain notices these changes and sends a signal down (via the spinal cord). The communication between the brain and the gut is also known as the gut-brain axis.

The upper digestive organs (the stomach and small intestines) do not hesitate for a second and respond to acute stress by tensing and relaxing less. As a result, the food slurry stays longer in the stomach and small intestines. As a result, you may have less appetite than usual during a stressful situation. Presumably this would be a defense mechanism of the body to prevent you from eating and/or vomiting. In addition, the body can now use the available energy for defying the stressful event (instead of for food digestion).

At the same time, the lower digestive organ, the enteric nervous system (or “brain” of the large intestines), responds by constricting and on the contrary tensing and relaxing more. Probably this is a defense mechanism of the body to eliminate toxins (danger). The more often these muscles tense and relax, the faster the stool is pushed forward. Normally, the large intestines still absorb fluid from the stool, making the stool harder. In the case of acute stress, there is often no time for this. You need to poop faster. Maybe even in the form of loose stools or diarrhea.

Stress and intestinal complaints

Furthermore, it has been found that the grinding and propulsive movements are more powerful in times of mental stress (e.g. during a meeting) than in times of physical stress (e.g. during a handball match). You can feel this difference. For example, some studies show that adults with acute mental stress develop a more sensitive stomach. They are more likely to experience pain or bloating. This makes them feel faster than usual that they have to poop. That feeling can last up to an hour after the stressful situation. In contrast, physical stress leads to a more insensitive abdomen. This makes you feel less quickly than usual that you have to poop. After all, you have to perform physically. That feeling disappears almost immediately after the stressful situation.

How your body (particularly the digestive tract) responds to acute stress depends on several things. What comes into play are, among other things, previous experiences, gender and intestinal complaints. For example, it is known that people with irritable bowel syndrome are more sensitive to acute stress than people without irritable bowel syndrome.

Temporary

Remember that the effect of acute stress on the digestive tract is less relevant than the effect of chronic stress on the digestive tract. If you handle acute stress well, its consequences will be as small as possible. In contrast, chronic stress poses greater health risks.

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