For people with constipation, where do all the feces they hold in go?

Friends with constipation always have this doubt:

I only have a bowel movement for several days, where does the unpooped shit go? It couldn't really be "eaten" by the intestines as the rumors say, right?

In fact, there are many people who have such doubts. After all, the frequency of defecation in patients with chronic constipation is generally once every 3 or 4 days, and it may even last for more than a week.

I haven’t been to the tuba for so long. Where did the poop that had accumulated in my body for several days go? 01 The formation process of stool

To understand where unexcreted stool goes, we must first look at the formation process of stool. The essence of poop is actually composed of undigested food residues, water, bacteria, mucosal cells shed by the intestines and other substances that we eat.

The digestive system of our body is like an efficient factory. Its operation mode is as follows: after the food is initially processed by the mouth → it enters the stomach along the esophagus → and then passes through the stomach and The small intestine digests most of the food → food residues that cannot be absorbed by the body carry water, electrolytes, some bacteria, mucosal cells shed by the intestines and other substances and flow to the large intestine → forming the initial shape of stool.

At this time, these newborn stools are still in a liquid state and contain a lot of water. However, in the large intestine, part of the water and electrolytes in the new stool will be absorbed by the large intestine, completing a shaping process from liquid stool to banana-shaped stool.

These successfully shaped stools will follow the movement of the intestines from the colon to the rectum, and then be stored in the rectum. When the amount of stool is sufficient, the defecation nerve reflex will be triggered by the internal and external sphincter muscles. Release and pass the stool out of the body.

This is the entire process of normal stool from formation to expulsion. But for patients with constipation, this process is not smooth, especially in the large intestine. 02 ? The pathogenesis of chronic constipation

Why do they all have the same digestive (feces-making) mechanism? Some people’s stools go smoothly from formation to elimination, while some people’s stools go through many ups and downs and finally return to normal. What about "disappearing"?

In fact, this matter has a lot to do with the pathological mechanism of chronic constipation.

1. The colon transports slowly

If someone asks what is the longest part of the human body, then there is no doubt that it is the large intestine.

Our large intestine is roughly divided into colon and rectum. The total length of the colon is about 1.38 meters and the length of the rectum is about 0.12 meters.

After digestion in the small intestine, food residues will be transferred to the colon of the large intestine. The colon then absorbs the excess water in the stool and plasticizes the stool into a banana shape.

As for the rectum, it becomes a "stool bank" that stores shaped stool. Intestinal movement is like a logistics system that transports shaped stool from the colon to the "stool reservoir" in the rectum. In reality, any logistics delivery may be late, let alone the intestines, which are not subject to the subjective control of the human brain.

Generally speaking, it only takes 1 day for normal people to transport stool from the colon to the rectum. However, for patients with constipation, this process may take 2 to 3 days or even longer due to the slow movement of the colon. . Did you see that some people are already lagging behind others on the road? This situation is medically called slow transit constipation.

2. Abnormal defecation reflex

Patients with constipation may have difficulty defecating and may have abnormal defecation reflexes.

According to the normal defecation response, water is absorbed through the colon, and stool shaped into a banana shape will be transported to the "stool reservoir" of the rectum due to intestinal movement. When stool is stored in the rectum, the large intestine triggers nerve receptors in the rectum, which transmit the sensation of defecation to the brain.

Then the brain issues instructions to press the anal sphincter, pelvic floor muscles, and rectal muscles to work together, and the rectal muscles exert force to squeeze stool out of the rectum. The anal sphincter relaxes and the stool is expelled from the body. Complete the entire act of defecation.

If the defecation reflex is abnormal, the muscle movement of defecation is uncoordinated, and the intestinal nervous system operates abnormally, it will cause difficulty in defecation. This condition is called outlet obstruction constipation. The stool at this time did not disappear, but was blocked in the rectum and could not come out.

However, because the space in the rectum is limited, part of the stool that has not been expelled will return to the colon, become blocked in the colon, and continue to be absorbed by the colon until it becomes dry and hard, from soft to yellow. Banana poop turns into black, hard nutty poop.

It will be even more difficult to defecate next time.

Sometimes, for healthy people, defecation is not so smooth. When you want to defecate, your brain will judge whether the current time is suitable for defecation. For example, when you are in a meeting or traveling and cannot find a bathroom, it will even forcibly ignore or reject the "defecation intention" transmitted by the rectal nerve receptor.

At this time, the rectum is screaming "I need to poop", but the brain can only resist the urge to poop, telling the sphincter to hold on and never poop. Holding in stool will also cause the stool to return to the colon, and then the colon will absorb water and turn into black and hard nutty stool. It will not be so easy to pass it later. Regularly holding in your bowels can lead to constipation over time.

03 ? Where does the stool go when you are constipated?

According to the above digestive operation mode, intestinal defecation mode and constipation mechanism, it is obvious that stool that has not been excreted for several days is still in your intestines when you are constipated. It may be slowly on its way from the colon to the rectum (slow transit constipation); it may also be that after finally reaching the rectum, it cannot get out at a place separated from the anal sphincter (outlet obstructive constipation); or even It is possible for both conditions to occur at the same time (mixed constipation).

The specific situation of these stools and the type of constipation require a professional doctor to clarify the specific situation after professional examination. After being rejected by the anal sphincter, the poop sadly returns to the colon. The colon continuously absorbs water, turning them from "small fresh poop" into "old poop", waiting for the next opportunity to be excreted.

Image source: Public account "Real World Research on Constipation"

And poop is not easy to bully. These "old poop" stay in the intestines for a long time and play a role in the bacteria. A large amount of harmful substances are produced under the conditions, such as methane, phenol, ammonia, etc. These substances are partially absorbed and then spread to the central nervous system, possibly affecting the body's brain function. Those behaviors of "holding in stool" may at least affect the quality of the next bowel movement, or at worst may turn into constipation, and may also trigger a series of adverse reactions in the body.