1, abdominal pain is generally paroxysmal severe colic. The pain is light at the beginning, then the condition increases, and after the peak of colic, the pain gradually decreases until it disappears. After a few moments, the above symptoms come on again. In strangulated intestinal obstruction, the abdominal pain is often persistent with paroxysmal intensification. 2.Vomiting The early stage of obstruction is reflex vomiting, and the vomit is food or gastric juice. In high small intestinal obstruction, vomiting is more frequent, and a large amount of gastric juice, duodenal fluid and bile is vomited. In low small bowel obstruction, there may be a 1-2 days vomiting resting period, followed by vomiting again, and the vomit is fecal-like material with fecal odor. In case of strangulated obstruction, the vomit may be bloody or coffee-colored. 3.Abdominal distension usually appears some time after the occurrence of intestinal obstruction. The degree of abdominal distension is related to the site of obstruction. In high intestinal obstruction, abdominal distension is mild, but sometimes a gastric pattern is seen. Low obstruction is manifested as full abdominal distension, often accompanied by intestinal type. 4.Anal stop defecation When acute complete intestinal obstruction occurs, there is no defecation and defecation in the anus. In the early stage, due to the increase of intestinal peristalsis, the gas and feces remaining below the obstruction can still be discharged. Therefore, the diagnosis of intestinal obstruction cannot be ruled out by a small amount of defecation in the early stage. In strangulated intestinal obstruction, bloody liquid or jam-like stool may be passed.