The sentence "difficulty comes from" is correct and usable in written English.
You can use it to explain where something difficult comes from, for example, "The difficulty of the assignment comes from the complexity of the material."
Part of the difficulty comes from an unwillingness to sit down and do the math.
A second difficulty comes from Fredrickson's insistence that racism must involve both difference and power.
Much of the difficulty comes from the weather: coming near the end of the rainy season, heavy downpours often turn sections of the course into a mudbath.
Bottomley told MPs that "the greatest difficulty comes from the way the lease is written, as lawyers do not normally spot that the ground rent has been doubled back to the time when the lease was originally granted".
Computers are hyper-literal, ornery beasts: anyone who has tried programming one will tell you that the difficulty comes from dealing with the fact that a computer will do exactly and precisely what you tell it to, stupid mistakes and all.
The greater difficulty comes from its highly variable character.
Her difficulty came from a habit of reticence that had once been a strength.
Once I had the hang of it, the only driving difficulty came from other, rubber-necking drivers.
A lot of the family's difficulty came from the delay in the death certificate, which the estate planning lawyers I spoke with said was not typical.
The singer explained writing the lyrics was not hard, but the difficulty came from being real and actually writing about her true feelings.
Part of the airlines' difficulties comes from a special provision of the bankruptcy code that protects secured lenders and lessors to airlines, said Lynn M. LoPucki, a law professor at the University of California at Los Angeles.
