As the weather turns cooler in autumn, the number of patients with diarrhea increases again. According to the statistics of intestinal clinics of major hospitals, the majority of patients with diarrhea caused by improper diet and cold, with the largest increase in recurrent diarrhea and chronic diarrhea. According to the doctors, these patients look “nervous”, have abdominal pain, urgent stools, and frequent loose stools, but the laboratory tests do not have viral bacteria, but they are not cured for a long time and have habitual diarrhea. Irritable bowel syndrome (IBS) is common in patients with crampy abdominal pain, abdominal flatulence, and changes in bowel habits. Some patients have symptoms of constipation (difficult or reduced bowel movements), others have diarrhea (frequent loose stools with a frequent sense of urgency to pass stools), and others have experienced both diarrhea and constipation. Sometimes patients have crampy abdominal pain and want to pass stool but cannot. In the past, there have been many medical names for the manifestations of irritable bowel syndrome, such as mucous colitis, allergic colitis, colonic spasm, intestinal cramps, and functional bowel disease. Most of these names are inaccurately defined. For example, colitis implies inflammation of the colon, yet irritable bowel syndrome does not cause an inflammatory lesion. Because doctors do not find organic pathology, irritable bowel syndrome is often thought to be caused by emotional conflict or stress. However, studies have shown that while depression, anxiety and stress in life can exacerbate the condition, other factors are also important. Studies have found that the colonic muscles of people with irritable bowel syndrome spasm at the slightest stimulus, and that the colon is more sensitive as well as more reactive than normal, thus responding to stimuli that would not affect most people. Medical studies have shown that common events such as eating, abdominal distention and accumulation of colonic food can cause allergic reactions in patients with irritable bowel syndrome. Certain medications or foods may trigger colonic spasms in some people. Sometimes the intestinal spasm delays the passage of stool and leads to constipation. Chocolate, dairy products or large amounts of ethanol are often triggers, and caffeine can cause loose stools in many people, but is more likely to affect people with irritable bowel syndrome. Studies have also found that women with irritable bowel syndrome have worse symptoms during menstruation, suggesting that fluctuating hormone levels can exacerbate symptoms in people with irritable bowel syndrome.