There are numerous things which nullify Sawm, to mention but a few:1- Sexual intercourse:
If the fasting person, who is of sound mind and resident, has sexual intercourse during the days of Ramadan, their Sawm is no longer valid. Thus, one must make up for that day, plus paying the Kaffarah (expiation), i.e., emancipating a believing bondsman. If one fails to find a bondsman, they have to observe Sawm two successive months; and if they are unable to do so, then they are to feed sixty Miskins (needy people) by giving out half a Sa` (1 Sa`=3 kg. Approx.) of the staple food each. A woman shares the same ruling if she is resident, of sound mind, and not coerced.2- Ejaculation: Resulting from kissing, touching (a woman's body), or gazing (stealthily at women). Thus, one's Sawm is no longer valid, and one has to make up for that day only, without Kaffarah.3-
Intentional eating and drinking: As for someone eats or drinks forgetfully, their Sawm remains valid. This includes all that enters one's stomach such as food or water. In addition, there is what is called Sa`ut, which means sniffing water into one's stomach through the nose. Also, medical nutrients nullify one's Sawm. (Part No. 9; Page No. 179) All these invalidate one's Sawm and require Kaffarah.4- Intentional bloodletting: Whether through Hijamah (cupping) or drawing a large quantity of blood; all such things invalidate one's Sawm and require Kaffarah.
5- Intentional vomiting: That is to eject the stomach contents, i.e., food and drink, through the mouth. This invalidates one's Sawm and requires Kaffarah, but if one vomits unintentionally, then the Sawm remains intact.In brief, these are the nullifiers of Sawm. However, some Muslim scholars, may Allah have mercy on them, fully explained these rulings that cannot be mentioned in detail here.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.