There are many causes of left abdominal pain, and the choice of department should be based on the accompanying symptoms. If it is accompanied by abdominal distention, bloating, vomiting and nausea, you may choose gastroenterology. Some people with left abdominal pain accompanied by rectal diseases, such as rectal polyps and rectal mucosal prolapse, are often accompanied by constipation, blood in the stool and difficulty in defecation, so they can directly choose anorectology. When left abdominal pain is accompanied by a change in bowel habits and a lump in the abdomen, you should be alert to the possibility of a tumour in the left side of the intestine and need to be seen by a gastroenterologist or oncologist. Some women experience left abdominal pain as a result of gynaecological disorders, accompanied by abnormal leucorrhoea, and need to be seen by a gynaecologist.