Erythromycin ointment as well as Yunnan Baiyao can be used for anal fissures combined with localized ulcers, but it is recommended that they be applied separately. Erythromycin ointment has an anti-infective effect and can be used for anal fissures combined with localized ulcers to control bacterial infections that have already occurred or may occur. Yunnan Baiyao can control the local bleeding and pain of anal fissure, and at the same time have a certain effect on wound healing, can be used. However, it is recommended that the two drugs be applied separately and not mixed. It should be noted that drug allergy is prohibited to use the above drugs, pregnant women are prohibited to use Yunnan Baiyao. If the local redness, swelling, irritation and other manifestations occur after the use of the drug, it is recommended to wash and consult a doctor. Erythromycin ointment and Yunnan Baiyao need to be used under the guidance of clinicians.