Irritable bowel syndrome (IBS) is the most common and important functional disorder of the gastrointestinal tract. It is a group of intestinal dysfunction syndromes consisting of abdominal discomfort or abdominal pain with abnormal bowel movements and changes in stool characteristics. Its occurrence is related to abnormal intestinal dynamics, infection and dysbiosis, visceral hypersensitivity, neuroendocrine immune abnormalities, and psychological factors. Diagnosis is not easy Patients with IBS have symptoms such as abdominal pain and discomfort, bloating, bowel sounds, diarrhea and constipation. The main symptoms of constipation type IBS are constipation, abdominal pain and bowel rumbling. In addition, patients may have indigestion symptoms such as epigastric discomfort, fullness, belching and nausea, and are often accompanied by palpitations, shortness of breath, chest tightness, red face, sweaty hands and feet, polyuria and other manifestations of imbalance in the vegetative nervous system. Experts say that the pathophysiology of the disease is not well understood. Some tests suggest that the patient may have some kind of intrinsic abnormality in the intestine, with no bowel movement on weekdays and pain caused by irritation of the intestine when feces accumulates to a certain extent in the intestine. However, no histomorphological changes could be detected, and the syndrome is practically devoid of inflammatory lesions. Patient mood swings such as anxiety, anger, confrontation, depression, and fear are usually triggers for the development of IBS. Depending on the clinical presentation, IBS can be classified as constipated, diarrheal, or mixed. Those with predominantly colonic motility disorders are more common and mostly present with pain in the mid or lower abdomen. It is usually aggravated by food or cold drinks and relieved after defecation, exhaustion and enema. Abdominal pain is often accompanied by increased frequency of defecation, a feeling of dyspareunia and abdominal distension, and the stool can be thin or dry. When colonic spasm persists, propulsive peristalsis is reduced, causing painful constipation. This condition can be called spastic constipation. Cases with predominantly colonic secretion dysfunction are rare. The patient does not have significant abdominal pain, but has frequent or intermittent diarrhea with paste-like feces containing a lot of mucus, sometimes with very little fecal matter, and generally normal fecal microscopy. A mixture of the two types mentioned above, in which constipation and diarrhea alternate irregularly and intermittently. In the diagnosis, it should be noted that the disease is mostly seen in young adults, more in men than in women, with a slow onset, a persistent course over years, or recurrent episodes, with varying severity of symptoms, and a good general condition. Secondly, the clinical condition of the disease is closely related to emotions, sensitive to diet, cold, exertion and other factors and easy to trigger, often accompanied by insomnia, anxiety, mental laxity, headache, forgetfulness, hypersensitivity and other symptoms. The patient is sensitive to drugs, and the first dose is effective, but the second dose is ineffective. The patient’s symptoms are mainly abdominal pain, mostly distension or cramping pain, with the left lower abdomen being the most common site. The abdominal pain can be relieved or relieved after defecation or bowel movement. The bowel habit often changes, accompanied by loss of appetite, belching, abdominal distension, intestinal tinnitus and indigestion. There may be no positive findings on physical examination, or there may be light pressure pain in the left lower abdomen, or striated intestinal tubes may be found. Laboratory examination shows more mucus in the stool; no red or white blood cells on microscopic examination; negative bacterial culture; negative occult blood test. X-rays and barium enemas showed no positive findings, or the colon was irritated. Endoscopy shows hyperactive intestinal motility or even spasm, no abnormal mucosa, and biopsy is basically normal. There are many ways to treat IBS, and the following drugs are mostly used for traditional treatment: 1. Antispasmodics. Abdominal pain can be treated with anticholinergic drugs such as atropine, probenecid, scopolamine, etc., but attention should be paid to adverse reactions. Relatively specific intestinal smooth muscle calcium channel antagonists can also be used, such as pivetonium bromide. 2. Antidiarrheal drugs. Loperamide or compound diphenoxylate can be used for diarrhea, but attention should be paid to constipation, abdominal distension and other adverse reactions. Mild cases can be used adsorbent, such as double octahedron montmorillonite. 3, laxative. Constipation can use laxative drugs, generally advocate the use of mild laxatives to reduce adverse reactions and drug dependence. Commonly used are volume-forming drugs such as oxytetracycline or methylcellulose, osmotic light laxatives such as polyethylene glycol (PEG4000), lactulose or sorbitol. 4, intestinal power sensory modulation drugs. The 5-HT4 receptor partial agonist tegaserod has been reported to be effective in improving constipation, abdominal pain and bloating, and is suitable for patients with constipated IBS. 5. Antidepressants. For abdominal pain symptoms and the above treatment is not effective, especially with more obvious psychiatric symptoms can be tried. The current study concluded that IBS patients have intestinal flora dysbiosis and small intestine bacterial overgrowth syndrome, the amount of total anaerobic bacteria, bifidobacteria and lactobacilli, which account for the major proportion of fecal flora, is reduced, while Clostridium difficile, which accounts for a smaller proportion of intestinal flora and is potentially pathogenic, is significantly increased. Bifidobacterium trisporus capsule Pefikon contains Bifidobacterium, Lactobacillus and Streptococcus faecalis, which are physiological bacteria of the human body, forming a biological barrier of the intestine, preventing the invasion and colonization of pathogenic bacteria, having nutritional and protective effects on the human body, antagonizing pathogenic bacteria, reducing the source of intestinal endotoxins and lowering the level of endotoxins in the blood. Constipated IBS patients can be treated with oral pefikon (capsule). Bifidobacterium, Lactobacillus acidophilus and Streptococcus faecalis contained in Pefikon can colonize the upper, middle and lower parts of the intestine respectively, inhibit harmful bacteria in the whole intestine, eliminate harmful substances in the whole intestine and resist the invasion of foreign microorganisms, which has obvious anti-infective effects. These three kinds of bacteria have their own characteristics: the upper part is Streptococcus faecalis, aerobic bacteria, the fastest reproduction rate, peaking within 12 hours; the middle part is Lactobacillus acidophilus, part-time anaerobic bacteria, 24 hours into the growth stability zone; the lower part Bifidobacterium anaerobic bacteria, 48 hours into the growth stability period. This makes up a joint flora that can grow under different conditions, with fast and long-lasting effects. It forms a biological barrier on the whole intestinal mucosa surface, which can inhibit harmful bacteria in the intestine, such as Salmonella, Shigella, pathogenic Escherichia coli and Vibrio cholerae. As a result, the intestinal function can be improved for therapeutic purposes. In addition, Bifidobacterium bifidum can produce a variety of organic acids during the metabolic process, which can lower the intestinal pH and promote intestinal peristalsis, thus relieving constipation. Patients with diarrhea type IBS can add Simethicone, whose main component is double octahedral montmorillonite particles with laminar structure and non-uniform charge distribution, which has fixing and inhibiting effects on toxins and pathogenic bacteria in the digestive tract and the toxins produced by them, and has the ability to cover the mucosa of the digestive tract, which can improve the defense function of the mucosal barrier against attack factors. The combination of the two drugs can not only supplement probiotics, but also antagonize pathogenic bacteria and consolidate the mucosal barrier, which is more effective in the treatment of diarrhea-type irritable bowel syndrome.