A custom that a man begins to observe Sawm only after having circumcision
If the case is as you mentioned that you had
reached the age of fifteen and had not observed Sawm because of the prevalent ignorance of Shari`ah rulings thinking that a man should not observe Sawm until he is circumcised, and that after your circumcision you were recovering from surgery and did not complete the Sawm of Ramadan, it is Wajib (obligatory) on you to make up for the missed days in Ramadan after reaching puberty. If you do not know the exact number of these days, you should base their number on the most likely estimation. Ignorance is not an excuse for the one who lives in an Islamic country. Since you delayed making up for breaking Sawm of these days until the following Ramadan, you should make up for them in addition to feeding a Miskin (needy) for each (Part No. 9; Page No. 315) missed day. The amount of food to be given is approximately one kilo and a half of the staple food of the country.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.