— Actions that “Do Not” Invalidate the Fast
1) Eating & Drinking Forgetfully
Narrated Abu Huraira (ra):
The Prophet (ﷺ) said, “If somebody eats or drinks forgetfully then he should complete his fast, for what he has eaten or drunk, has been given to him by Allah.”
Sahih al-Bukhari 1933
2) Vomiting involuntarily
Narrated Abu Hurairah (ra):
The Prophet (ﷺ) said: if one has a sudden attack of vomiting while one is fasting, no expiation is required of him, but if he vomits intentionally, he must make expiation.
Sunan Abu Dawud 2380
3) Wet Dream
“If a man experiences a wet dream this does not invalidate his fast, because it was involuntary on his part; it is similar to the case when something enters his throat whilst he is sleeping.”
See al-Mughni by Ibn Qudaamah, vol. 3, p. 22
4) Medical Purposes under certain conditions
Enemas, eyedrops, eardrops, tooth extraction and treatment of injuries do not invalidate the fast.
Medical tablets that are placed under the tongue to treat asthma attacks etc, so long as you avoid swallowing any residue.
Insertion of anything into the vagina such as pessaries, or a speculum, or the doctor’s fingers for the purpose of medical examination.
Insertion of medical instruments or IUD into the womb.
Anything that enters the urinary tract of a male or female, such as a catheter tube, or medical scopes, or opaque dyes inserted for the purpose of x-rays, or medicine, or a solution to wash the bladder.
Fillings, extractions or cleaning of the teeth, whether with a siwaak or toothbrush, so long as you avoid swallowing anything that reaches the throat.
Rinsing the mouth, gargling, sprays etc. so long as you avoid swallowing anything that reaches the throat.
Oxygen or anaesthetic gases, so long as that does not give the patient any kind of nourishment.
Anything that may enter the body via absorption through the skin, such as creams, poultices, etc.
Insertion of a fine tube via the veins for diagnostic imaging or treatment of the veins of the heart or any part of the body.
Insertion of a scope through the stomach wall to examine the intestines by means of a surgical operation (laparoscopy).
Taking samples from the liver or any other part of the body, so long as that is not accompanied by administration of solutions.
Endoscopy, so long as that is not accompanied by administration of solutions or other substances.
Introduction of any medical instruments or materials to the brain or spinal column.
Reference:
https://islamqa.info/…/things-that-invalidate-the-fast