Many patients suffer from chronic abdominal pain, or symptoms such as bloating, constipation, diarrhea, and mucous fluid stools. When they go to the hospital for colonoscopy, they find that the intestinal mucosa is congested and edematous, and the diagnosis of colonoscopy is “chronic colitis”. If treatment is given according to this diagnosis, it may not be possible to treat the patient at all. This is because this patient may not be enteritis, but only intestinal dysfunction, and the congestion and edema of the intestinal mucosa found by colonoscopy is only artificially caused by taking laxatives before the colonoscopy. If the patient is treated according to enteritis, it will not be cured. If you come across some overly concerned patients who repeatedly do colonoscopy, you may be repeatedly diagnosed with chronic colitis. What exactly is this type of patient’s disease? In fact, most of them are gastrointestinal dysfunction, and those who have stomach pain are often suffering from irritable bowel syndrome, which means that the intestines are easily agitated and easily stimulated to spasm causing abdominal pain, which is also too much said to be gastrointestinal neurosis, as the name implies, is also easily affected by emotions. This abdominal pain is more variable in location and may move, mostly in the lower and left lower abdomen, mostly relieved after defecation and exhaustion, without progressive aggravation, and asymptomatic at night after sleep. Diarrhea is often a small amount of loose, unformed stools, and may have a more urgent bowel movement or a sense of incomplete bowel movement. The stool is mostly with mucous membrane fluid, but without pus and blood. In some patients, the diarrhea alternates with constipation, and the stool is dry and may be in the form of sheep feces. It is often accompanied by significant neuropsychiatric symptoms such as insomnia, anxiety, and depression. Physical examination often has no positive findings, no fixed pressure pain, and sometimes a spastic sigmoid colon with pressure pain can be palpated in the left lower abdomen. Due to the lack of specific physical examination and signs of biochemical abnormalities in this disease, repeated examinations of patients often hold complaints that doctors cannot detect the disease. Irritable bowel syndrome is a group of symptoms including abdominal pain, abdominal distension, abnormal bowel habits and stool characteristics, and is a gastrointestinal tract dysfunctional disease. The onset of the disease is mostly related to abnormal gastrointestinal dynamics, hyperresponsiveness of intestinal motility and abnormal sensitivity of visceral sensation caused by various stimuli such as food, gastrointestinal hormones, prostaglandins and intestinal lumen expansion. In addition, psychosomatic disorders are an important factor in the development of the disease. Patients are mostly young and middle-aged people aged 20 to 40 years old, and women are more common. The disease is recurrent and prolonged, with symptoms that affect the quality of life and cause a great psychological and economic burden. The main treatment is life conditioning, symptomatic treatment, improvement of gastrointestinal dynamics, release of intestinal spasm and reduction of intestinal gas production, etc., supplemented by the necessary psychological treatment. To date, there is no one method or definite efficacy. In view of the complex etiology and diverse clinical manifestations, full communication with patients and psychological counseling should be provided to eliminate patients’ concerns, establish a good doctor-patient relationship, and improve patients’ confidence in treatment. The principle of combining comprehensive and individualized treatment is emphasized, and treatment is graded according to the type and severity of the main symptoms. Lifestyle modifications, such as avoiding excessive fat and stimulating foods such as coffee and alcohol, regular physical exercise, and reducing reactions to various stresses, are sufficient to achieve treatment goals. Reduce the intake of gas-producing foods, such as dairy products and soybeans, in the daily diet. Patients with predominantly diarrhea should limit coarse vegetables as well as fruits as appropriate. Patients with mainly constipation should advocate the intake of fiber-rich foods to increase stool volume, relieve constipation, and reduce abdominal pain.