Blood Tests, Injections and Fasting

As a doctor, I have some difficulty during Ramadan when Muslim patients present themselves for tests and treatment (or I am asked about what is permissible by non-Muslim colleagues for their patients). Notwithstanding that one should not fast if it is a danger to one's health, what are the positions regarding the following (non-urgent) treatments or tests for a patient who is fasting:

Wa Alaykum Assalam wa Rahmatullah wa Barakatuhu,

In the Name of Allah, Most Merciful & Compassionate

From a previous question answered by Faraz Rabbani:

No, a blood test does not invalidate the fast, as it is merely the taking out of blood.

The fast is invalidated when anything enters the body cavity, which is why injections and drips (even those that have nutritive value) do not invalidate the fast. [Bada'i` and Masa'il al-Siyam]

Wassalam,

SunniPath Fiqh Team