Abdominal pain and bloody stool may be caused by the following reasons: First, patients with ulcerative colitis. It is mostly seen in young and middle-aged patients and belongs to an autoimmune disease. The patient will have long-term abdominal pain, diarrhea, abdominal distension, mucus, pus, blood or bloody defecation. Second, malignant tumors of the intestine. It is mostly seen in middle-aged and elderly people, with obvious changes in bowel habits and rules, irregular stool, bloody stool, and even anemia and hypoproteinemia. Later, it is easy to develop intestinal obstruction or intestinal tube rupture. Third, there may be serious anorectal diseases. For example, patients with severe hemorrhoids accompanied by anal fistula will have lower abdominal pain accompanied by bloody stool.
