Why can I travel a thousand miles if I hold my urine in, but cannot walk an inch if I have diarrhea?

Have you noticed? Holding in diarrhea is much more difficult than holding in urine. There is a saying that goes like this, you can travel a thousand miles by holding your urine, but you can't walk an inch by holding your urine. First, it is related to the conduction process. Let’s first talk about how the urge to urinate arises. The bladder is a specialized urine storage organ. The bladder capacity of a normal person is generally 300 to 500 ml, and can reach a maximum of 800 ml. When the bladder stores too much water, the pressure increases, and the receptors receive signals that reach the brain through conduction pathways, thus producing the urge to urinate. So how did we hold it in? We can subconsciously make our sphincter muscles contract more beautifully. Of course there is a limit. If the pressure in the bladder exceeds 6.86 kPa, it will cause you great pain and you will not be able to hold it in anymore. Of course, normal people can still hold it in for a long time in the online environment. Second, it is different from the bladder, a specialized storage tool. Human feces is produced along with intestinal peristalsis and pushed to the workplace. We often act as a temporary storage container. When the volume of feces reaches a certain level, the nerve stretch receptors in the intestinal wall receive signals and transmit the signals through the primary defecation reflex center. Go to the cerebral cortex and let you mutate. Although we can also let the brain issue instructions to control the mutation, the whole thing will shrink back with the muscle contraction, and let the absorption and digestion factory above reprocess it to further reduce its size. , thus causing you to mutate and disappear. Third, muscle control abilities are different. When we have a lot of stool or have loose stools, our mutations become difficult to control. Take diarrhea as an example. If the frequency of diarrhea increases significantly during diarrhea, our intestinal mucosa will be congested and edematous. The perianal muscles will also be congested and edematous, which will lead to a decrease in muscle contraction ability and make it difficult to defecate. In addition, as we issue orders, our goalkeeper, the external anal sphincter, is very unimportant. The continuous contraction can generally only last about 55 seconds. Otherwise, those fluid poops will spurt out in spurts, embarrassing you. Fourth, holding in your feces and urine is not a good habit. It should be avoided as much as possible to avoid causing harm to the body.