From your description, it is evident that you are infected with genital warts which is otherwise called condylomata acuminate. They are seen on the anal regions only. This is one of the widely transmitted sexual disease or STD. These warts are caused by human papilloma virus of HPV. There are about 40 types of HPVs seen, causing various sexual diseases. These warts are highly contagious and can be transmitted to your sexual partner easily. Due to its high risk of transmission there are no 100% effective solutions to prevent transmission. Protected sex using condoms and by avoiding sexual contact of the affected regions can help in reducing transmission. Avoiding sexual contact with those infected people and those who have taken vaccination will help. Using new condoms every time while having sex will reduce the risk to an extent. However, there are treatment options available to treat this condition. Treatments include application of creams like warticon, cryogenic treatment or frozen killing and surgery. Creams that can be applied directly on skin include Podophyllin, Podoflox, Imiquimod etc. Surgeries may be required to remove larger warts. Some warts are widespread and do not respond to medications. In such cases also, surgeries will be required. Surgical excision and Electrocautery are found more effective than cryotherapy or frozen killing. Hope I have answered your query. Take care.