Surgery is an important tool in the work of surgical treatment and the key to success or failure of treatment, but the exposure, incision, hemostasis and suturing in surgery are also different degrees of injury and anatomical dislocation to patients, which will inevitably cause different degrees of complications. Common postoperative complications in gastrointestinal surgery include: 1. Postoperative bleeding: Postoperative bleeding can occur in the surgical incision, abdominal cavity and gastrointestinal tract. Imperfect intraoperative hemostasis, incomplete control of traumatic bleeding, diastole of the original spastic small artery dissection, detachment of the ligature wire and coagulation disorders are all causes of postoperative bleeding. Clinically, the presence and extent of bleeding can be roughly determined based on the patient’s vital signs, the concentration and speed of blood in the drainage fluid (gastric tube, abdominal drainage tube) and abdominal circumference, and the diagnosis can be clearly made by ultrasound, laparotomy and gastroenteroscopy. When the drainage is ≤100ml/hour and the patient’s vital signs are stable, the patient should be generally observed and the bleeding should be stopped by medication. When the drainage is ≥100ml/hour and the patient’s vital signs are stable, surgery should be performed again to stop the bleeding. 2, intestinal leakage: detachment of the ligature line, poor blood flow and edema of the suture tissue, and lack of careful anastomosis are common causes of intestinal leakage. The diagnosis of intestinal leakage can be confirmed by the presence of bile, intestinal fluid and fecal fluid in the abdominal drainage fluid. When intestinal leakage occurs when it has been confined to the extent that diffuse peritonitis does not occur, it can generally heal spontaneously with non-surgical treatment (fasting, drainage, etc.), while when diffuse peritonitis occurs when intestinal leakage occurs, surgical intervention is needed to make it become the above-mentioned condition or heal spontaneously or with stage II surgical intervention. 3, abdominal abscess: underlying diseases with intra-abdominal infection or even abscess, surgical abdominal contamination (such as intestinal obstruction bowel decompression, intestinal anastomosis, etc.), and intestinal leakage are common causes of abdominal abscess. Abdominal abscesses can be considered clinically in the presence of paralytic intestinal obstruction, painful pressure masses and systemic infectious toxicity, and ultrasound, CT and abdominal puncture can make a clear diagnosis. Abdominal abscess can be treated conservatively when there are no systemic symptoms. Once systemic symptoms appear, the abscess should be drained by puncture under ultrasound guidance or by surgical incision and drainage. 4.Adhesive intestinal obstruction: any abdominal surgery can cause adhesions, but adhesions do not always cause intestinal obstruction. Only when the adhesions lead to narrowing of the intestinal lumen, angulation, torsion and other effects on intestinal peristalsis and expansion will cause intestinal obstruction. Clinically, intestinal obstruction manifests as abdominal pain, abdominal distension, nausea and vomiting, and anal stoppage of defecation and exhaustion. Simple incomplete intestinal obstruction often improves with non-surgical treatment. Recurrent attacks or strangulated intestinal obstruction should be treated surgically. 5. Incisional infection: It is the most common postoperative complication. Intraoperative measures such as strengthening incision protection, incision flushing, thorough hemostasis and elimination of dead space should be taken to prevent incision infection. The diagnosis of incisional infection should be considered after 2-3 days of postoperative increase in body temperature, swelling or throbbing pain of the incision, local redness, swelling and pressure pain, etc. The diagnosis can be confirmed by the ultrasound finding of fluid under the incision and the exclusion of pus from the incision. Adequate drainage and regular drug changes are the most effective way to treat incisional infection. Some of the incision infections need II sutures after cure.