Bab 263: Chapter 260

While they're talking the others go check on the merchants, healing those who are still alive, but returning with bad news about the others. 

"The Gnolls mangled the bodies too badly. No point in resurrecting a body missing vital organs." The primary Healer for the patrol announces upon his return to the group. 

There is a gap in what healing spells can do. While alive, they can regrow lost limbs, organs and much more. But after death, regular healing has no effect, only resurrection. So if a body is missing essential parts necessary for life, they can't be resurrected in the conventional sense. Cain had heard and seen that the undead don't require all their organs, so they could be brought back that way, but not to true life.

Some species like vampires also have the ability to function without parts of their body for a time until they can be reattached. Even that has its limits though.