What is the ruling of the Sharia concerning a man who has been away from his sick wife for four years and is no longer able to have intercourse with her, and what is the ruling on his wife fasting Ramadan if she is sick?

Kindness to one's wife and good companionship are noble traits. The husband did well to refuse adultery as a means of treatment. The solution to this problem is for him to marry another woman. This is permissible in Islamic law, provided he is able to be just, and it may even be desirable or obligatory in his situation. The wife's consent is not a condition, and the claim that she might die due to his marrying another may be an illusion. Let him seek Allah's help and proceed with the marriage.