Rectal cavity administration, also called rectal insufflation, is a completely painless, minimally invasive modern ozone therapy for systemic administration of ozone. It should be performed after defecation or enema. During the treatment, a mixture of ozone and oxygen is introduced into the colon through a catheter. Ozone helps eliminate inflammation and kills pathogens such as bacteria, viruses, parasites and yeasts. It can help restore a healthy intestinal flora. Some ozone is absorbed by the colon wall, and the oxidation by-products such as RoS (reactive oxygen species) and LoP (lipid oxidation products) can enter the liver through the portal vein, which has the same therapeutic effect as the major auohemotherapy, and furthermore, it is easy to be accepted by children, the elderly, and patients with venipuncture difficulty in major autohemotherapy. Through rectal perfusion, more than 80% of ozone can be absorbed by the body. However, it should be noted that the ozone dose used in this method should not be introduced more than 500 ml at a time to prevent rupture of the colon.