Is it permissible to seek treatment with one who claims that he has dealings with a doctor from among the Muslim jinn?
Question

                If I seek treatment with a man who has with him Muslim doctors from among the jinn, will that invalidate my fast?.
Praise be to Allah.Firstly: 
It is not 
    permissible to seek the help of the jinn for medical treatment or anything 
    else, and it is not permissible to go to one who claims to do that. 
The Muslim 
    should not be deceived by the success of anyone’s treatment or seeing the 
    effects of that, for the Dajjaal will tell the sky to rain and it will rain, 
    and he will tell the earth to bring forth its treasure and it will do so. 
    Should the Muslim be deceived by him and believe his claims? It may be a 
    test or a gradual punishment from Allaah. “We shall gradually seize them 
    with punishment in ways they perceive not” [al-A’raaf 7:182].  
Shaykh ‘Abd 
    al-‘Azeez ibn ‘Abd-Allaah ibn Baaz (may Allaah have mercy on him) was asked 
    about the ruling on using the services of Muslim jinn to treat disease if 
    that is needed. He replied: 
The sick 
    person should not use the services of the jinn for treatment or ask them for 
    anything, rather he should ask well known doctors, but he should not turn to 
    the jinn, because that is a means that leads to worshipping them and 
    believing them. Among the jinn are some who are kaafirs and some who are 
    Muslims, and some who are innovators, and you do not know about them. So you 
    should not rely on them or ask them for anything, even if they appear to 
    you. Rather you should ask the people of knowledge and human doctors. Allaah 
    condemned the mushrikeen as He said (interpretation of the meaning): 
“And 
    verily, there were men among mankind who took shelter with the males among 
    the jinn, but they (jinn) increased them (mankind) in sin and transgression”
    [al-Jinn 72:6] 
And it is a 
    means that leads to dependence upon them and shirk, and it leads to seeking 
    benefit from them and seeking their help, and all of that is shirk. End 
    quote. 
Majallat 
    al-Da’wah (no. 1602, Rabee’ al-Awwal 1418AH, p. 
    34) 
Shaykh 
    Saalih al-Fawzaan (may Allaah preserve him) said: 
The help of 
    the jinn should not be sought, whether from the Muslims among them or those 
    who say that they are Muslim, because he may say that he is Muslim but he is 
    lying in order to interfere with people. This should be prevented from the 
    outset. It is not permissible to seek the help of the jinn even if they say 
    that they are Muslims, because this opens the door to trouble. 
It is not 
    permissible to seek the help of one who is absent whether he is a jinni or 
    otherwise, and whether he is a Muslim or not. Rather we should seek the help 
    of one who is present and is able to help, as Allaah said of Moosa 
    (interpretation of the meaning): 
“The man 
    of his (own) party asked him for help against his foe”
[al-Qasas 
    28:15]
Moosa was 
    present and able to help, and it was possible for him to help as this was an 
    ordinary situation. End quote 
Al-Sihr 
    wa’l-Sha’wadhah, p. 86, 87 
Secondly: 
With regard 
    to fasting, it is valid in sha Allaah and is not invalidated by that, 
    although the reward for fasting may be reduced and may be erased altogether 
    by the commission of sin. See the answer to question no.
    50063. 
And Allaah 
    knows best.