Bloating and pain in the abdomen with blood in the stool, it has many causes. The first common cause is mixed hemorrhoids, which is a mass of varicose veins that cause pathological hypertrophy of the anal cushion when the abdominal pressure increases or when constipation occurs, and then moves down and out of the anus. If the mixed hemorrhoids are combined with stage 2, 3 and 4, it will easily lead to enlargement of the tortuous hemorrhoid veins and hypertrophy of the hemorrhoid nucleus, so it may produce small abdominal distension and pain. The second common cause is a submucosal abscess of the rectum, for example, an infection can lead to an abscess under the rectal mucosa, which can cause abdominal distension and pain. If the abscess breaks down, it can sometimes lead to blood in the stool. The third common cause may also be rectal malignant tumors, which can easily erode the submucosal vessels of the rectum and cause bleeding if there is a long history of malignant disease. Therefore, there are many reasons for the above symptoms, and rectal diagnosis and, if necessary, anoscopy or colonoscopy should be performed in a timely manner to clarify its cause.