The insertion of an equipment or tube through veins to connect arteries and veins of the heart, or anywhere in the body. This kind of treatment is used sometimes for diagnostic purposes to detect clots in veins and arteries, and sometimes for therapeutic purposes, such as opening some closed arteries or arteries in which blood was congealed.
It was stated in decision of the International Islamic Fiqh Academy that catheter does not affect the fast because it is not included in the things that invalidate the fast and does not even take the same ruling of things that invalidate the fast.
In case this catheter is accompanied by gel or a fatty substance, it invalidates the fast as mentioned in the gastroscope.
It is a scope that is inserted into the patient's abdomen through a small opening in the abdominal wall to reach the abdominal cavity, and not to the stomach. It may be used for therapeutic purposes, such as cholecystectomy, appendectomy, or for removing specific gallstones, and sometimes it is used for diagnostic purposes such as X-rays, or to take samples from the liver and so on.
The most correct view is: it does not affect the fast because it enters the body from an unusual access, so it is not included in the Shari`ah texts, nor in the meaning of things that invalidate the fast. The decision of the International Islamic Fiqh Academy was issued with the same ruling, but if it is accompanied by fatty substances, it invalidates the fast.
14- Dialysis: There are two ways for dialysis:
First, Using an instrument called artificial kidney, where blood is drawn to this device, then the device filters the blood from harmful substances, and then blood returns to the body intravenously; during this process, the body may need nutritious fluids that are given intravenously.
Second, through the peritoneum membrane in the abdomen. A small tube is inserted in the abdominal wall above the navel, then about two liters of fluid, containing a high percentage of glucose, are inserted into the abdomen. It remains in the stomach for a while, then it is pulled out again. However, this process is repeated several times during the day. Scholars have differed in this regard, but the most correct view is: if it is accompanied by nutritious liquids, it invalidates the fast because, although it is not food or drink, it takes the same ruling of food and drink because it benefits the patient.
However, if it is meant for filtering the blood only, it will not affect the fast.