If he refuses to take the medicine is his disobeying his father?
Question

                1- I am an asthmatic patient. I normally go to hospital during the course of the year. They were giving me cortisone which had an effect on my bones. So I stopped taking it fearing that my health becomes worse, which made my father angry. Am I considered disobedient for this?

2- I suffer from excessive gas, so I pass wind a lot. How shall I purify myself for prayers?

For these reasons I cannot walk a lot, and after I stopped taking the cortisone I became even more ill, so I was ordered by the doctor to stay at home. Thus I cannot go to the masjid a lot except for Friday prayer, Am I sinning?.
Praise be to Allah.Firstly: 
We ask Allaah to heal you 
    and reward you for what has befallen you. 
Secondly: 
If the medicine is harming 
    you and affecting your bones, then there is nothing wrong with stopping it, 
    because you do not have to take that which will harm you, whether it is 
    medicine or anything else. The Prophet  (peace and blessings of Allaah 
    be upon him) said: “There should be neither harming nor reciprocating harm.” 
    Narrated by Ahmad and Ibn Majaah (2341) and classed as saheeh by al-Albaani 
    in Saheeh Ibn Majaah. 
But you should consult a 
    doctor about that, because the harm caused by not taking it may be greater 
    than the harm caused by taking it. 
You should weigh up the 
    interests served by taking the medicine and its harmful effects, and the 
    harmful effects caused by not taking it. 
If it is proven that the 
    medicine is harmful to you, then your refusing to take it is not 
    disobedience towards your father, because obedience is only required in that 
    which is good and proper, as the Prophet  (peace and blessings of Allaah 
    be upon him) said: “Obedience is only in that which is good and proper.” 
    Narrated by al-Bukhaari (7257) and Muslim (1840). 
Thirdly: 
You should look for a 
    remedy for passing too much gas, so that you can perform the prayer with 
    proper focus and peace of mind with the congregation. If it is continuous 
    and does not stop for long enough for you to do wudoo’ and pray, then this 
    is called “wind incontinence”, and in that case it is sufficient for you to 
    do wudoo’ after the time for prayer begins, and pray the obligatory prayer 
    and whatever naafil prayers you want with that wudoo’, and it will not 
    matter if you pass wind even when you are praying. 
But if the wind stops for 
    long enough for you to do wudoo’ and pray, then you must offer the prayer at 
    that time, even if that means that you do not pray in congregation in the 
    mosque. 
Fourthly: 
If going to the mosque will 
    harm you or is too difficult for you, there is nothing wrong with you 
    offering the prayer in your house, because Allaah says (interpretation of 
    the meaning):  
“So keep your duty to 
    Allaah and fear Him as much as you can”
[al-Taghaabun 64:16]
“Allaah burdens not a 
    person beyond his scope”
[al-Baqarah 2:286]
Whenever you feel energetic 
    and strong, you can go to the mosque. 
We ask Allaah to heal you 
    and make you well. 
And Allaah knows best.