Can Satan cause someone to have any physical ailments or disease?
I tend to believe he can to certain individuals. But this must be viewed through God's knowledge of all who are His.
With Job, a child of God, Satan could do nothing to him until God's protection was removed. (Job 1:10) But when God did remove that protection, Satan was able to affect sickness upon Job. (Job 2:7)
And I believe this is true of all believers. I'm not saying all sickness a believer gets is from Satan. It may just be he caught a sickness. But if it is from Satan, it is only because God removed His protection and for His purpose.
As to those who are not God's people, and God knows who all are, I tend to believe Satan has a freer hand in directing sickness on someone, for whatever reason. But even then God may not allow it for His reasons. And just because a person who is not one of God's people gets sick, doesn't mean it directly came from Satan. He may just have caught a sickness.
One thing for sure, all sickness and disease of man originated with Satan as he caused the fall.
Just my opinion.
Brings up an interesting question. Do fallen angels ever get sick? Or, if not, why not?
Lees