6- Anesthetic gases:
If a Muslim takes anesthetic gases through the nose or through the mouth, the International Islamic Fiqh Academy reached a decision that it does not affect the fast because it is not food or drink nor something of the like. These gases are not composed of parts but they are inhaled through breath, then go to airways; so they do not reach the throat. In case they reach the through, the amount will be small and can be overlooked as the remaining water after rinsing the mouth.
Except in one condition if some chemicals were inserted with the scope and these chemicals are composed of parts; in this case it invalidates the fast.
However, if these gases are taken through any access other than the mouth and the nose, such as veins, they do not affect the fast.
As for the person under drug, if he is totally under drugs, does that affect the fast because his mind is gone by drugs? This issue is based on jurists’ views regarding the fast of a person who passes out. They have explained the issue in detail; if a person is under drugs during the whole day, from dawn to sunset, he has to make up for the fast according to the majority of scholars because fasting is abstaining from food, drink, and sexual intercourse with an intention and that did not happen due to drugs. It was reported in the Hadith: “He leaves food, drink, and sexual desire for My Sake.” [Reported by Al Bukhari]. So, a person should abstain from these things with the intention of obeying Allah. However, measuring drugs on a sleeper is not correct because a sleeper has a consciousness; unlike the one who is under drugs and who had lost his entire consciousness and his fast is invalid.
If anesthesia continued only for a part of the day, the most correct view of scholars is that the fast is valid as long as he made the intention of fasting (i.e., he did not want to break his fast).
As for the local anesthesia, which does not cause a person to lose senses nor awareness but only in the position of the operation, it does not affect the fast because a person still has his mental faculties and still has the intention truly.
7- Ear drops and ear wash:
The correct view regarding ear drops or ear wash is: they do not affect the fast because ears are not access to the throat. Therefore, a Muslim does not break his fast if he uses ear drops or ear wash, but if there is any ventage that causes the liquid to reach the throat, it has different ruling: If the liquid is small, where it does not exceed the overlooked amount of ablution, it will not affect the fast, but if it is much, as in the case of washing the ear with solution or a liquid that penetrates to the throat and a Muslim swallows it, it invalidates the fast.