ISIS militants are faking illnesses to get out of fighting

There's a term US soldiers give to one of their own who tries to shirk duty by making constant medical appointments: Sick call commando.

It looks like ISIS has the same problem.

Documents seized last month by Iraqi forces at a former ISIS base in Mosul, Iraq reveal that, despite its ability to recruit religious fanatics to the ranks, the so-called Islamic State has its fair share of "problem" fighters who don't actually want to fight, The Washington Post reports.

The Post found 14 fighters trying to skate their way out of combat, to include a Belgian offering a note about having back pain, and a Kosovar with "head pain" who wanted to be transferred to Syria.

Another, a recruit of Algerian descent from France, told his superiors he wanted to return home and offered two suspicious claims: I'm sick, and if you send me home, I'll continue to work remotely.

"He doesn't want to fight, wants to return to France. Claims his will is a martyrdom operation in France. Claims sick but doesn't have a medical report," one note reads, according to The Post.

Of course, there are plenty within the ranks of ISIS who are still fighting on the front lines. But to see that at least some are trying to get out while they still can seems to suggest that the US and Iraqi military is doing something right.

Iraqi forces captured all of eastern Mosul late last month, and preparations are currently being made to start hitting the western side of the city. The top US general in Iraq, Lt. Gen. Stephen Townsend, is confident that both Mosul and the ISIS capital of Raqqa will fall "within the next six months."