There are two categories of nullifiers of fast:
1. nullifiers that entail redemption (qadaa).
2. nullifiers that entail redemption of the day or days invalidated (qadaa), and expiation, (kaffaarah).
Nullifiers that entail redemption (qadaa).
The first nullifiers are when the fast is rendered invalid and it must be redeemed after Ramadan in a period extending over eleven months, but no later than the next Ramadan.
The nullifiers are:
1. Intentionally eating or drinking by allowing food and drink to travel through the mouth or nose to the stomach. When this happens, the fast is nullified, even if it is just a bite or a sip.
On the other hand, if eating or drinking occurs unintentionally, by mistake, and, for example, if a person forgetfully drinks after jogging, the fast is correct and resumes and no redemption is necessary provided the faster does not continue to eat or drink after he remembers. This ruling rests on the hadith narrated by many reporters by way of Abu Hurairah (raa) that the Prophet (saas) said: "Whoever forgets -while fasting - and eats or drinks, should stop immediately and resume or complete his fast. For he has just been fed and quenched by Allah." (Agreed Upon)
The hadith indicates there is no need to worry if forgetfulness overcomes a faster causing him or her to eat or drink. Besides, Allah (SWT), in His mercy, justifies the person continuing to fast because the sustenance that he took was a direct gift from Allah, to the faster. The believer must be aware that this phenomenon occurs usually in the first few days of the fast, before the body and the mind adjust themselves to the new eating schedule.
2. A substitute for food and drink is as good a nullifier of fast as the real thing. By food substitute we mean two things:
Giving a faster blood transfusion due to the loss of blood resulting from an injury, invalidates the fast, the reason being blood is a form of nourishment like food. Is not one of the reasons for eating to get the blood flowing within our system?
Feeding an individual through the stomach, or intravenously, (through the veins), parenteral feeding (injecting nutrients into the body) as a substitute for food and drink invalidates the fast. Because this is a substitute for food it takes its case in nullifying the fast.
3. Inducing vomiting nullifies the fast. By this is meant, intentionally causing the contents of the stomach to be ejected through the mouth either by wringing the stomach, palpating the throat, or by smelling or looking at an emetic substance. In this case, the fast should be redeemed later or after Ramadan, but if the fast is a Sunnah fast, one has a choice to make it up later or not. In a hadith related by Abu Hurairah (raa) the Messenger of Allah (saas) said: "Whoever is overcome by vomiting wouldn't have to make it up, but if vomiting is the result of inducement (the fast is invalidated) and would have to be made up." (Ahmed)
It is important to say that the amount of the ejected contents, whether it is little or much, has no effect on the ruling.
One of the reasons why induced vomiting invalidates fasting is when the contents of the belly are thrown up, the body, which is already short on nourishment, is further weakened. Therefore, the Lawgiver as mercy tells the believer to go ahead and break this day and make it up later.
However, no faster should break his fast because he or she feels nausea until the vomiting occurs.
4. Bleeding as a result of menstruation (known as hayd), or post-childbirth bleeding, (nifaas), nullify the fast, even if it occurs moments before sunset and the iftar time. In this case, the fast is no longer valid, and even if the woman tried to continue, it would still not be valid. It has been reported that the Prophet (saas) said regarding menstruation, "when a woman experiences her monthly period, she will not pray or fast, but she shall redeem the fast after Ramadan, but not Salaat."
5. Ejaculation of semen, as a result of kissing, hugging, using the hand (as in self-pollution), or using any object for a sexual purpose for both men and women invalidates the fast because this is shahawah, a sensuous or lustful act that nullifies the fast. In a hadith Al-Qudsi, the Messenger of Allah (saas) has been reported as saying referring to the faster: "He who abstains from his food, his drink and his lustful desires for My (Allah) sake." (Al-Bukhari)
But if ejaculation occurs as a result of a wet dream, or just unintentional thinking that is devoid of actual acts or inducements, the fast remains valid. Allah (SWT) will not hold one responsible for things randomly thought of which do not accompany the deed. The Messenger of Allah (saas) said: "Verily, Allah has pardoned my community, (Ummah) what their souls entertain in so far as they do not do or speak." (Agreed upon) This citation is referring to the case of thoughts borne in mind. There are bad thoughts and good thoughts. The bad thoughts and intentions are left unpunished so far as they are not rendered into deeds, a blessing from Him (SWT). For were He to hold us accountable for our thoughts, man would not have been able to escape His wrath. On the other hand, a good thought is rewarded regardless of whether the thought is being rendered into a deed or not.
In a hadith, related by Ibn Abbas (raa) the Messenger of Allah (saas) conveying the Message from His Lord, says: "Allah has written down the good deeds and the bad ones. Then He explained it (by saying that) he who has intended a good deed and not done it, Allah records it with Himself as a full good deed, but if he has intended it and has done it, Allah records it with Himself as from ten good deeds, multiplied to seven hundred times, or many times over. But if he has intended a bad deed and has not done it, Allah records it with Himself as a full good deed, but if he has intended it, and has done it, Allah records it as one bad deed." (Bukhari/Muslim)
Nullifiers that entail redemption of the day or days invalidated (qadaa), and expiation, (kaffaarah).
When a faster intentionally has marital relations with his wife during the daytime, the fast is invalidated. This is the most serious of fast breakers. That is why, besides redeeming the day, there is kaffaarah mughallazah, severe expiation to be observed after Ramadan.
There is a precedent to this case during the time of the Prophet (saas) as related by Abu Hurairah (raa) who said a man came to the Messenger of Allah and said: "I am ruined, O Messenger of Allah." The Prophet (saas) asked Him, "What ruins you?" He replied: "I had marital relations with my wife in Ramadan." The Messenger of Allah (saas) asked him, "Do you have a bondsman to free as an expiation?" He said No. The Messenger of Allah (saas) asked him again, "Are you able to fast for two consecutive months?" No, he said. The Messenger of Allah (saas) asked again, "Do you have enough to feed sixty poor people?" No, he said. As the Messenger of Allah (saas) sat, someone, brought a sack full of dates. The Messenger of Allah (saas) gave the dates to the man and told him to expiate with it (by giving it to the poor). The man said, "Is there anyone poorer than I am, within the innermost part of this city? Indeed, there is no household in more desperate need than us." The Messenger of Allah (saas) laughed until his teeth and gums could be seen. He said to him, "Then go and feed your family." (Jama'ah, including Bukhari and Muslim)
This hadith indicates many important points. First, what constitutes expiation is one of the three following things:
1. Freeing a person in bondage, man or woman. If a man did not have a bondman, he could purchase one and set him free. By the way, this was one way Islam combatted the institution of slavery.
2. Fasting two consecutive months.
3. Feeding sixty poor people an average meal. Indeed, the severity of the penalty is indicative of how serious the offense is.
According to Jamhur, the majority of the scholars, both the man and his wife are responsible for making up the expiation, provided both intentionally committed the offense during the daytime, while both had intended to fast that day. But, if he forced his wife during Ramadan to have relations with him, both will redeem the day, but he will be the one to expiate. If she is not observing fast for some reason, there will be nothing due to her.
Others said, regardless of whether he forced her or not, only the man should expiate because in the hadith, the Messenger (saas) commanded the man, not the woman, to expiate. However, the previous explanation is stronger.
Another point discussed is which is the best among the three choices of expiation: freeing, fasting, or feeding? Whichever is easier for the expiator is the one he should do. There is another hadith by Abu Hurairah (raa) in which the Messenger of Allah (saas) told a man who broke his fast to free a person or fast for two consecutive months or feed sixty indigent. This report, by the way of Muslim, demonstrated that one has a choice.
What happens to a person who has sex during fasting, but before he expiates he repeats the offense? How many expiations should he make? There will be only one expiation. It is like in prayer when a worshipper makes two mistakes in one prayer, he makes only one correction. But if he has expiated for the first offense and then repeated the offense, the scholars agreed that expiation is due for the second offense. The Jamhur of scholars infers from hadith that the expiation is dropped because of poverty. Allah is the best knower.