Patients with AIDS do not present with obvious clinical signs of blood in the stool. AIDS is a clinically common sexually transmitted disease caused by HIV infection. When HIV first infects a patient, the patient will have flu-like symptoms such as headache, fever, fatigue, and swollen lymph nodes, which are not accompanied by blood in the stool. These symptoms can slowly subside on their own within a month or so. When a patient enters the onset of AIDS, he or she will have a wide variety of infections and tumors, and will have recurrent fever, weight loss, diarrhea, etc., and will not have blood in the stool. If a patient suspects that he has AIDS after having high-risk sex and has blood in his stool, he should go to a regular hospital for consultation.