Left-sided abdominal pain and vomiting may be gastritis, pancreatitis, bacillary dysentery, etc., need to consult a doctor in a timely manner, under the guidance of the physician for the cause of the medication or surgery and other treatments. 1. Gastritis: For gastritis caused by left-sided abdominal pain and vomiting, you need to use proton pump inhibitors, such as omeprazole, lansoprazole, and so on, as well as to promote gastrointestinal dynamics of the drug, such as domperidone, mosapride and so on under the guidance of the doctor. For gastritis caused by Helicobacter pylori infection, it needs to be treated with quadruple therapy as prescribed by the doctor, i.e., two antibiotics + proton pump inhibitor + bismuth, such as metronidazole, amoxicillin, pantoprazole, bismuth potassium citrate and so on. 2. Pancreatitis: patients with left-sided epigastric pain and vomiting caused by pancreatitis first need to fast and undergo gastrointestinal decompression. In addition, it is also necessary to follow the doctor’s instructions with pancreatic enzyme-activated growth inhibitors and their analogs, such as octreotide, Lanreotide, etc.. When the pain is more severe in some patients, non-steroidal anti-inflammatory drugs such as ibuprofen and acetaminophen can be used under medical supervision. In addition, patients can also take percutaneous puncture drainage, laparoscopic surgery, pancreatectomy and other treatments. 3. Bacterial dysentery: If the left side of the abdominal pain caused by bacterial dysentery and vomiting, you can use cefixime, azithromycin and other antibiotics under the guidance of the doctor. Some patients with severe abdominal pain can also be prescribed with atropine, scopolamine and other antispasmodic drugs. Left-sided abdominal pain and vomiting may also be caused by ulcerative colitis, intestinal tuberculosis and other diseases, it is recommended that the patient should consult a doctor in time, the doctor will choose the appropriate measures according to the cause of treatment.