As a general rule and definite decree, injecting nourishment through serum in order to provide body resistance to a patient invalidates fasting. Injection in order to reduce the pain or for obligatory treatment invalidates fasting according to Abu Hanifa.However, it does not invalidate fasting according to Imam Abu Yusuf, Imam Muhammad and other madhhab imams. As a precaution, it is better to carry out those treatments at night. However, that permission can be used for the treatments that have to be carried out during the day. Gynecological examination does not invalidate fasting.

The judgments that the Directorate of Religious Affairs (of Turkey) made regarding the methods of examination and treatment that invalidate and do not invalidate fasting:

The Supreme Committee of Religious Affairs conducted a meeting under the presidency of Deputy Director Prof. Dr. M. Saim YEPREM on 22/09/2005.

The issue of “The Methods of Examination and Treatment That Invalidate and Do Not Invalidate Fasting” prepared by the Committee of Answering Religious Questions was negotiated. As a conclusion of the negotiations, the following decisions were made;

Many people undergo treatment due to various health problems. Today, many methods of treatments that did not exist during the age of Hazrat Prophet have emerged. Some of the patients who undergo treatment want to perform fasting. However, they have doubts whether those methods of treatment and examination invalidate fasting or not, and they ask our directorate about them.

Fasting, which is one of the five fundamentals of Islam, is, according to its definitions in the verses of the Quran, a kind of worship that is performed by restraining oneself from eating, drinking and sexual activity from dawn to dusk. The following is stated in the Glorious Quran, “Permitted to you on the night of the fasts, is the approach to your wives (...) Eat and drink, until the white thread of dawn appear to you distinct from its black thread.” (al-Baqara 2/187). Hazrat Prophet said; “Every (good) deed of the son of Adam would be multiplied, a good deed receiving a tenfold to seven hundredfold reward. Allah, the Exalted and Majestic, has said: ‘With the exception of fasting, for it is done for Me and I will give a reward for it, for one abandons his passion and food for My sake.’ ” (Muslim, Siyam, 30, H.No: 1151). Accordingly, fasting consists of abstaining from eating, drinking and sexual activity with the intention of worshipping; if one of those is carried out, fasting is invalidated. All of the Islamic scholars agree on it. As for the issues except eating, drinking and sexual activity, there are disagreements because they were either decided by analogy or by acting upon the meaning of imsak (seizing or abstaining) in the word “siyam” by mujtahids (Islamic legislators); many scholars expanded the things that invalidate fasting while some scholars kept them to a minimum acting upon the meaning of fasting in the verse and hadith.

In addition to eating, drinking and sexual activity, nothing that invalidates fasting except vomiting a mouthful intentionally and hajamat (a kind of cupping; drawing blood) is mentioned in hadiths (see Ibn Majah, Siyam, 18; Abu Dawud, Siyam, 28; Tirmidhi, Sawm, 25). However it is mentioned in the hadiths that many acts like having a bath, rinsing out the mouth (mazmaza), brushing teeth(using miswak), tinging with kohl, kissing one’s wife, applying oil on one’s body, wearing perfume do not invalidate fasting (see Bukhari, Sawm, 24, 27; Muslim, Siyam, 12; Tirmidhi, Sawm, 29, 31, 76; ─░bn Majah, Siyam, 17; …).
Fasting is a kind of worship that all Muslims must know about how to perform, what invalidates and what does not invalidate it. Therefore, as in the other kinds of worshipping, Hazrat Prophet would have explained in detail if there had been other things that invalidated fasting, and his companions would have reported them to the following generation. However, apart from the acts that were mentioned above, there are no other hadiths that were reported whether sahih (sound), da’if (weak), musnad (indexed by Sahaba) or mursal (reported by Tabi’in).

Some acts that are mentioned among the things that invalidate fasting in our fiqh resources like amma (deep wound in the head) or jaifa (deep wound in the abdomen) and huqna (enema) were carried out during the time of Hazrat Prophet and Muslims probably faced them and carried out those treatments but no narration was reported from our Prophet stating that they invalidated fasting. As a matter of fact, it is a necessity of tabligh (conveying the message) that the Prophet must explain the things that Muslims can face. Therefore, only eating, drinking and sexual activity that are stated clearly in the Quran and sahih sunnah invalidate fasting. It corresponds to restraining oneself from the desires of the soul and bodily habits that our religion means by fasting.

In the light of the explanations above, methods of examination and treatment can be evaluated as follows in terms of invalidating or not invalidating fasting:

a) Sprays for the patients of asthma
A very small amount (1/20 ml.) of the spray that lung patients use is delivered into the mouth at one time. Most of it is absorbed by the mouth and the wall of the trachea and disappears. There is no certain information that the rest reaches the stomach with the saliva. When that amount is compared to the water that remains in the mouth during wudu (ablution), it can be seen that it is very little. As a matter of fact, there is a hadith (Darimi, Sawm, 21) and the consensus of Islamic scholars that if the water remaining in the mouth after wudu reaches the stomach, it does not invalidate fasting. In addition, it is inevitable that some bits and chemicals from miswak (natural toothbrush) will reach the stomach but it is mentioned in sahih hadith resources that Hazrat Prophet used miswak while he was fasting. (Bukhari, Sawm, 27; Tirmidhi, Sawm, 29). On the other hand, fasting is not invalidated by something that is not certain whether it reaches the stomach or not according to the rule “what is known as certain is not invalidated by doubt”.

Therefore, if asthma patients do not have any other diseases and if their health is suitable for fasting, their fasting is not invalidated by the medicine containing oxygen that is sprayed into the mouth in order to enable them to breathe easily.

b) Eye Drops
According to the information received from the specialist opticians, a dosage of eye-drop that should be taken over a period of time is very little (50 microliters which is 1/20 of a milliliter), and some of it is thrown out by the blink of an eyelid, and some of it is absorbed in the eye, in the canals connecting the canals between the eye and the nasal cavity and in the mucus through pores, and scarcely any amount of it may arrive in the alimentary canal. When that information is considered together with the explanations above, eye drops do not invalidate fasting.

c) Nose Drops
One drop of medicine dropped into the nose for treatment is about 0,06 cm3. Some of it is absorbed through nose walls and only very little of it reaches the stomach. It can be evaluated as exempt as it is the case in mazmaza.

d) Sublingual Pills
The sublingual pill placed under the tongue in some cardiac diseases is absorbed through the mouth tissue, mixes with the blood and prevents heart attack. Since that pill is absorbed and disappears in the mouth, it does not reach the stomach. Therefore, sublingual pills do not invalidate fasting.

e) Endoscopy, colonoscopy, ultrasound from the anus or vagina
In endoscopy, which is carried out in order to determine the disease in the stomach by inspecting the stomach or carrying out a biopsy, a medical instrument is inserted through the mouth into the stomach, and the instrument is taken out after the procedure. In colonoscopy, which is carried out in order to determine the disease in the colons by inspecting the inside of the intestine or carrying out a biopsy, an instrument is inserted through the anus into the intestines, and the instrument is taken out after the procedure. In colonoscopy, almost always, and in endoscopy generally some water is sent into the body through the instrument in order to clean the area to be inspected.
Although endoscopy, colonoscopy, ultrasound from the anus or vagina do not mean eating or drinking, they invalidate fasting because water is generally sent into the body through the instrument. However, if water, oil or any other thing that has the quality of food does not enter into digestive system during those procedures, endoscopy, colonoscopy, ultrasound from the anus or vagina will not invalidate fasting.

f) Inspecting urinary canal and inserting medicine into the canal
The instruments or medicine inserted into the urinary canal do not invalidate fasting.

g) Anesthesia
Preventing transmission in various levels on the neural pathways that transmit pain forms anesthesia. There are three kinds of anesthesia: local, regional and general. In small operations, the anesthesia that is attained by administering drugs that prevent transmission to the immediate surroundings of the region to be operated on is called local anesthesia. The anesthesia that is formed by administering drugs to prevent transmission in the level of spinal cord in larger regions of the body, for instance, below the belt or one half of it to the spinal cord or before the spinal cord on the points of connection formed by a large neuron group is called regional anesthesia. The anesthesia in which the patient is anesthetized and the pain is prevented in the level of brain is called general anesthesia.
Anesthesia is formed through administering drugs into body through air passage or injection. The anesthesia that is carried out through air passage or injection does not reach the stomach, and it is not regarded as eating or drinking. However, in regional and general anesthesia, in emergencies, medicine, liquid and serum are administered through vascular access. Therefore, local anesthesia does not invalidate fasting. In regional and general anesthesia, fasting is invalidated because serum is administered.

h) Ear drops and having the ears washed
There is a canal between the ears and throat. However, since the eardrum blocks that canal, water or medicine does not reach the throat. Therefore, the medicine dropped into the ear and having the ears washed do not invalidate fasting. Even if there is a small hole in the eardrum, the medicine will not reach the stomach or very little of it will reach the stomach. As we have mentioned before, such a small amount is regarded exempt. However,if the eardrum membrane is pierced, water may reach the stomach during when one has his ears washed. Therefore, an amount of water that is enough to validate fasting reaches the stomach, fasting will be invalidated.

i) Suppositories and enema 
Suppositories are inserted as painkillers and antipyretics and for some other purposes through the anus, and in order to treat fungal infections and some gynecological diseases through the vagina. Enema is the procedure of injecting liquid through the anus in order to remove the feces in the large intestine before medical operations or in the treatment of constipation.
Digestive system starts in the mouth and ends in the anus; it consists of the alimentary canal and digestive glands. The alimentary canal starts in the mouth. After the mouth comes the pharynx. Then the esophagus, stomach, small intestine, large intestine, rectum and anus follow. Digestion is completed in the small intestine. In the large intestine, only water, glucose and some salts are absorbed.There is no connection between the vagina of a woman and the digestive system. 
Therefore, the suppositories that women insert through their vaginas do not invalidate fasting. As for the suppositories inserted through the anus, although they enter into the digestive system, they do not invalidate fasting because digestion is completed in the small intestine and the suppositories do not have any nutritious properties and they are not regarded as eating or drinking when they enter the body through the anus. .

Two situations occur during enema: since water, glucose and some salts are absorbed in the large intestine, fasting is invalidated if a liquid containing nourishment is administered into intestines or if an amount of water enough to invalidate fasting stays in the intestine. However, if the water is not kept in the intestines and if the intestines are cleaned immediately fasting is not invalidated because the water is taken out together with the feces in the intestines and the water absorbed during that period is very little.

j) Injections, giving serum and blood to a patient
Whether injections invalidate fasting or not depends on the usage purpose of them. Injections are given in order to relieve pain, to treat a disease, to increase the resistance of the body and to give nourishment, etc. The injections that do not give nourishment or pleasure do not invalidate fasting because they are not regarded as eating and drinking. However, the injections that give nourishment or pleasure invalidate fasting. The same rule is valid regarding giving the patient blood or serum.

k) Dialysis
The dialysis that is applied to the patients with renal failure are of two types:peritoneal dialysis and hemodialysis.
Peritoneal dialysis is the procedure of cleaning the blood from the harmful substances and maintaining fluid balance through a special solution administered into the abdominal cavity. Hemodialysis is the procedure of cleaning the blood through a machine outside the body and giving the cleaned blood back to the body. The blood is drawn through a syringe from the arm of the patient. The hemodialysis machine filters the blood through a dialyser continuously and removes the harmful substances and the extra water. The filtered clean blood is given back to the patient through a second syringe. During that procedure, sometimes, fluid containing nourishment becomes necessary to be given to the patient.
Accordingly, fasting is not invalidated if hemodialysis is carried out without giving any fluid containing nourishment to the patient. In the other forms of dialysis, fasting is invalidated since fluid containing nourishment is given to the body.

l) Angio
The operation known as angio by people is carried out for diagnosis (angiography) and for treatment. Angiography means the imaging of the veins and arteries. A drug called contrast substance that makes the veins visible is administred into the veins and films called angiograms are obtained. Thanks to angiography, the veins fostering the organs are imaged and diagnostic information regarding vascular diseases or the organs fostered by those veins are obtained. The classical method for the treatment of angio is angioplasty. It is carried out in order to reopen the narrowed or blocked veins through a special devices called balloon or stent.

In the light of that information, since nothing related to eating and drinking take place in both angiography or angioplasty, fasting is not invalidated.

m) Biopsy
Removing tissue from the body (biopsy) in order to analyze it does not invalidate fasting.

n) Donating blood
As to whether donating blood invalidates fasting or not, acting upon the hadith reported from Hazrat Prophet “The one administering the cupping and the one being cupped have both invalidated their fasts” (Abu Dawud, Siyam, 28), some Islamic scholars say donating blood invalidates fasting. Acting upon the narration that Hazrat Prophet was cupped while he was fasting (Bukhari, Sawm, 32; Abu Dawud, Siyam, 29), most of the scholars say that donating blood does not invalidate fasting.

When those two hadiths and other narrations are evaluated together, the hadith “The one administering the cupping and the one being cupped have both invalidated their fasts” should be understood as “The one administering the cupping and the one being cupped bear the risk of invalidating fasting.” The one administering the cupping bears the risk of swallowing blood since he sucks the blood and the one being cupped may feel weak and may have to eat and drink something. As a matter of fact,Anas b. Malik said cupping is not liked because it will weaken the fasting person. (Bukhari, Sawm, 32).
Therefore, donating blood does not invalidate fasting.

o) Ointment and bands containing medicine
Oil, ointment and similar things applied on the skin are absorbed through the pores and capillaries under the skin and mix with blood. However, the skin absorbs them in very small amounts and very slowly. On the other hand, it does not mean eating or drinking. Therefore, the ointment applied on the skin and the band containing medicine that is stuck on the skin do not invalidate fasting. 
In conclusion;

a) Our religion permits people who are ill and who are undergoing treatment not to perform fasting. Therefore, people who are continuing their treatment can delay performing fasting until they recover and their treatment is over. However, if they want to perform fasting in the month of Ramadan together with other people and if they do not have any other drawback to fasting, they can have their examination and treatment after iftar (breaking their fasting).
b) The spray used by asthma patients, eye, ear and nose drops, having the ear washed if the ear is not pierced, using sublingual pills, imaging the urinary canal, administering medicine into urinary canal, endoscopy on the condition that water, oil or a similar substance having the property of nutrition do not enter the body, colonoscopy, ultrasound through the anus or vagina, local anesthesia, enema on the condition that water is not kept in the intestines and the intestines are cleaned immediately, hemodialysis without administering the patient any fluid, injections that are not nourishing or that do not give pleasure, angio, biopsy, donating blood, applying ointment on the skin, sticking bands containing medicine on the body do not invalidate fasting.

c) Injections that are nourishing or that give pleasure, administering fluids that have nourishment to the body or enema that lasts so long enough as the water to be absorbed, endoscopy or colonoscopy if water, oil or a similar substance having the property of nutrition enter the body, regional and general anesthesia, having the ear washed if the ear is pierced so that an amount of water sufficient to invalidate fast reaches the stomach, peritoneal dialysis, and hemodialysis administering serum to the vein invalidate fasting.