First of all,
What is diarrhea? In fact, it mainly refers to the unusually high water content of feces.
Under normal circumstances, our intestines not only absorb nutrients in food, but also absorb water. The water in the intestine is in a slow and "slow-moving" state, so as to ensure that there is enough time to absorb the water in food residues.
Normally functioning intestines are generally not afraid of temperature and so-called general food stimulation. So not everyone has diarrhea when they catch a cold.
But just like our skin, the intestine is "fragile and sensitive".
Then why does "sensitive intestine (such as irritable bowel syndrome, or congenital intestinal dysfunction)" have diarrhea as soon as it catches cold? Let's take a look at this flow chart.
A cold (including drinking ice water and catching cold in the abdomen)-the relatively fragile and sensitive intestinal environment loses its temperature (the low temperature in the intestine stimulates nerves), which leads to intestinal spasm, hyperactivity of intestinal smooth muscle and peristalsis disorder-at this time, the intestine can't keep water and can't stop rushing to the end of the digestive tract with some small fragments in the intestine-diarrhea.
Attention,
First, the above is only the cause of diarrhea caused by intestinal sensitive person catching cold, not all diarrhea. Most diarrhea is due to intestinal inflammation or flora.
Second, diarrhea just can't retain water, not oil and sugar, so many patients with irritable bowel syndrome pull 3-5 times a day, but they are still extremely obese, and there is no conflict at all.
Children's intestines are more fragile, and it is more important for infants to keep warm. This is what old people often say, "Cover your stomach and don't catch cold."
It varies from person to person. Some people don't pull at all, while others pull at once. Just like skin allergies. Some people are allergic to blowing hot air conditioners, while others are fine. Skin allergy is skin immune resistance, and intestinal diarrhea is intestinal immune resistance.
There are many reasons for diarrhea, and catching cold is the most common one. In addition, there are inflammation, mental stress, flora imbalance, overeating, food allergies such as peppers. The whole gastrointestinal tract and its microbial system constitute the "digestive world" of the human body. In detail, it is not something that can be understood without a medical foundation (for example, if the small intestine decomposes more hydrogen, it is easy to have diarrhea, and vice versa). Regarding the microbial environment in the human body, because I have irritable bowel syndrome, I often pay attention to the relevant literature. In fact, the research level of the whole human being on the intestinal environment is still quite primary, and many problems have not been understood yet, and a lot of knowledge is still waiting for you to explore.