The traditional view is that the onset of FD is associated with delayed gastric emptying, postprandial restriction of fundic tolerance diastole, and visceral hypersensitivity; 2. 3. general infection: low degree inflammation of the GI tract causes GI mucosal barrier dysfunction, which makes the GI tract more sensitive to acid and fat, further affecting the brain-gut axis reflex and causing gastrointestinal motility disorders. Gastroenteritis can cause FD or FD combined with IBS. when the infection involves the stomach and proximal small intestine, it mostly causes FD, while when the infection involves the distal small intestine or colon, it mostly manifests as IBS. when the infection involves the whole GI tract, FD and IBS overlap syndrome may occur. 4. duodenal inflammation, especially eosinophilia, can cause FD; 5. food intolerance, allergy, and high-fat diet can also lead to FD; 6. psychosocial factors, especially anxiety, are significantly associated with the development of FD. In general, postprandial restriction of fundic tolerance diastole, visceral hypersensitivity, and delayed gastric emptying mostly cause PDS, while H. pylori infection, abnormal brain-gut axis reflex, acid exposure of the gastrointestinal tract, and gastrointestinal tract infection are associated with EPS. Clinical manifestations are a group of clinical syndromes, mainly characterized by epigastric pain, abdominal distension, early satiety, belching, and loss of appetite. The above symptoms can be persistent or recurrent, and may change during the course of the disease, and is one of the most common non-organic gastrointestinal diseases in gastroenterology. 1. Early satiety: a feeling of fullness soon after eating, leading to a reduction in dietary intake; 2. Upper abdominal distension: occurs mostly after meals, and may be persistent or may be aggravated after eating; 3. Often accompanied by belching and acid reflux, but nausea and vomiting are uncommon; 4. Some patients also have psychiatric symptoms such as poor sleep, headache, or have anxiety or depression. The diagnosis of the disease is an exclusive diagnosis, mainly following the Rome III criteria. The main points of diagnosis are as follows: 1) one or more symptoms that cause discomfort: postprandial fullness, early satiety, epigastric pain, burning sensation in the epigastrium, etc.; 2) no organic disease that can explain the above symptoms; 3) the appearance of symptoms 6 months before diagnosis and the accumulation of symptoms for more than 3 months in a year; 4) the presence of “alarm symptoms and signs” such as wasting, anemia, vomiting blood, black stool, dysphagia, abdominal masses, jaundice, etc. Patients with “alarm signs and symptoms” such as emaciation, anemia, vomiting, black stool, dysphagia, abdominal mass, jaundice, etc. should be thoroughly examined to find the cause. 5. For patients younger than 45 years old and without “alarming symptoms and signs”, the diagnosis can be aided by basic tests such as three major routine tests, liver and kidney functions, and abdominal B-ultrasound. Diagnostic treatment can also be given for 2-4 weeks. Patients who do not respond to treatment and whose dyspepsia symptoms are progressively aggravated need further examination to clarify the cause. Classification According to whether the symptoms are meal-related or not, they can be divided into two categories: 1. postprandial discomfort syndrome (PDS): dyspepsia symptoms are related to meals, mostly manifested as early satiety and postprandial bloating; 2. epigastric pain syndrome (EPS): non-meal-related dyspepsia, with symptoms mainly manifested as epigastric pain or burning sensation in the epigastrium. Treatment The treatment of FD is mainly symptomatic, the medication is mainly empirical, and the principle of comprehensive and individualized treatment is mainly followed in the treatment. Placebo: Placebo treatment can relieve FD symptoms in about 30% of patients; 2. Pro-gastrointestinal drugs: Pro-gastrointestinal drugs can benefit about 60% of FD patients. However, metoclopramide is not recommended for the treatment of FD because of its inaccurate effect and side effects. H.pylori eradication therapy: H.pylori eradication therapy is better than the placebo group, especially for patients with EPS; 4. Acid suppression therapy: Acid suppression therapy mainly includes two drugs, proton pump inhibitors and H2 receptor blockers. Clinical studies have shown that proton pump inhibitors can benefit reflux patients, but are not effective in patients with dysmotility, while H2 receptor blockers have no significant advantage over placebo treatment. 5, gastric mucosal protective agents: including bismuth, the gastric mucosal protective drugs are not significantly better than placebo treatment effect. 6.Anti-depressants/anti-anxiety drugs: Since brain-gut axis malfunction is involved in the pathogenesis of FD, antidepressants may be effective in FD symptom relief, and studies have shown that antidepressant therapy is better than placebo for FD treatment. When using antidepressant medications, tricyclic antidepressants are preferred over 5-HT reuptake inhibitors or norepinephrine reuptake inhibitors. Because psychosocial factors play a role in the development of FD and the available pharmacological FD treatment has limited effect, the treatment for FD should not ignore general treatment, such as explaining to patients that the disease is a non-organic lesion and does not affect life expectancy, and reducing patients’ tension and anxiety. Patients should be instructed to improve their lifestyle habits, avoid overeating, eat regularly, and reduce the intake of high-fat food, etc. Treatment of refractory FD 1. Giving H2 receptor antagonists after the ineffective use of proton pump inhibitors may still obtain symptomatic relief; 2. Drug combined with psychotherapy may have some effect; 3. If the patient still complains of pain after using the above strategies, consider giving adequate doses of tricyclic antidepressants, anxiolytics combined with antidepressants, antidepressants combined with pregabalin or gabapentin, but do not opioids are recommended.