I only defecate once every few days. Where's all the shit that hasn't been discharged? It won't really be "eaten" by the intestines, will it?

In fact, there are not a few people who have such doubts. After all, the frequency of defecation in patients with chronic constipation is usually once every 3 or 4 days, or even for more than a week.

I haven't defecated for a long time. Where's the shit I've been saving for a few days?

0 1 the process of stool formation to understand the whereabouts of the stool that has not been discharged, we must first look at the process of stool formation. In fact, the essence of poop is composed of undigested food residues, water, bacteria, mucosal cells shed from the intestine and other substances.

The digestive system of our body is like an efficient factory, and its operation mode is as follows: food is processed by the mouth → enters the stomach along the esophagus → digests most food through the stomach and small intestine → food residues that cannot be absorbed by the body bring water, electrolytes, some bacteria, mucosal cells and other substances from the intestine to the large intestine → forms the original shape of stool.

At this time, the feces of these newborns are still in a liquid state with high water content. However, in the large intestine, the feces of newborns will be absorbed by the large intestine to absorb some water and electrolytes, completing a molding process from liquid feces to banana feces.

These successfully formed feces will follow the intestinal movement from colon to rectum, and then they will be stored in rectum first. When the frequency of defecation is enough, it will trigger the nerve reflex of defecation, which will be released by the internal and external sphincter and excreted.

This is the whole process of normal stool from formation to discharge. But for constipation patients, this process is not very smooth, especially in the large intestine.

02 ? Why is the pathogenesis of chronic constipation the same digestive (fecal) mechanism? Some people's stools are smooth from formation to elimination, while some people's stools eventually "disappear" after layers of bumps?

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

1, colon slow transmission

If someone asks where the longest part of the human body is, it is undoubtedly the large intestine.

Our large intestine can be roughly divided into colon and rectum, in which the total length of colon is about1.38m and the length of rectum is about 0.12m.

After being digested by the small intestine, food residues will transfer to the colon of the large intestine. Then the colon absorbs excess water in the feces, which makes the feces plastic into a banana shape.

As for the rectum, it has become a "stool bank" for storing molded stools. Intestinal movement is like a logistics system, which transports the formed feces from the colon to the "feces bank" of the rectum. In reality, any logistics express delivery may be late, not to mention the intestines that are not under the subjective control of the human brain.

Generally speaking, it takes only 1 day for normal people to transport their feces from the colon to the rectum, while it may take 2~3 days or even longer for constipation patients because of the slow movement of the colon. Look, some poop, on the way, has been slow for a long time! This condition is called slow transit constipation in medicine.

2. Abnormal defecation reflex

Constipation patients have poor defecation and may have abnormal defecation reflex.

According to the normal defecation reaction, banana-shaped feces will be transported to the "feces bank" of the rectum because of intestinal movement to absorb water through the colon. When feces are stored in the rectum, the large intestine will trigger nerve receptors in the rectum, and the nerve receptors will upload the feeling of defecation to the brain.

Then, the brain gives instructions to expel the anal sphincter, pelvic floor muscles and rectal muscles, and the rectal muscles forcibly push the stool out of the rectum. Then the anal sphincter is relaxed and the feces are excreted. Complete the whole defecation behavior.

If defecation reflex is abnormal, defecation muscle movement is uncoordinated, and intestinal nervous system is abnormal, it will lead to defecation difficulty. This condition is called outlet obstructive constipation. At this time, the stool did not disappear, but it was blocked in the rectum and could not get out.

However, due to the limited rectal space, a part of the undrained feces will return to the colon, block up in the colon, and continue to be absorbed by the colon until it becomes dry and hard, and changes from soft yellow bananas to black hard nut feces.

It will be more difficult to discharge when you defecate next time.

Sometimes, for healthy people, defecation is not so smooth When you want to defecate, the brain will judge whether the time is suitable for defecation. For example, when you have a meeting and can't find a bathroom, you may even forcibly ignore or reject the "defecation" transmitted by rectal nerve sensory sources.

At this time, the rectum is clamoring for "defecation", but the brain can only resist this intention and tell the sphincter to hold on and never pull. It will also cause the stool to flow back to the colon, and then it will be absorbed by the colon into black hard-core stool, and then it will not be so easy to pass. Frequent defecation will lead to constipation over time.

03 ? Where did the stool go when constipation occurred? According to the above digestive operation mode, intestinal defecation mode and constipation mechanism, it is obvious that the feces that have not been discharged for several days during constipation are still in your intestines.

It may be on the way from colon to rectum (slow transit constipation); It may also be that after reaching the rectum, it can't come out where it is separated from the anal sphincter (outlet obstructive constipation); It is even possible that the above two situations occur at the same time (mixed constipation). The specific situation of these stools and constipation types need to be clarified by professional doctors after professional examination. After being rejected by the anal sphincter, the feces will sadly return to the colon, and they will be continuously inhaled by the colon, from "small fresh feces" to "old wax feces", waiting for the next opportunity to be excreted.

Source: WeChat official account "Constipation Real World Research"

And poop is not easy to bully. These "old poops" stay in the intestine for a long time, and under the action of bacteria, they will produce a lot of harmful substances, such as methane, phenol and ammonia. These substances are partially absorbed and spread to the central nervous system, which may affect the brain function of human body. Those "defecation" behaviors may affect the quality of the next defecation and turn into constipation, which may also trigger a series of adverse reactions.