Johnny Hill had 15 points and seven rebounds for the Redbirds (17-13, 8-9 Missouri Valley), who never trailed en route to ending a three-game losing streak.
Anthony Downing scored 12 points to lead the Bears (9-21, 6-11).
Illinois State led 43-25 at halftime and poured it on in the second half. The Redbirds used a 13-0 run to take a 59-34 lead, a surge punctuated when Carmichael was fouled while converting a thunderous dunk.
During the stretch, the Bears were held scoreless for five minutes. The lead later grew to 30 points at 66-36 after a dunk by Jon Ekey, as the Redbirds' run extended to 20-2 over a seven-minute period.
Guard Naz Mitrou-Long, whose 2015-16 season ended in December due to hip problems, has been granted a hardship waiver for the coming season, Iowa State said.
As the Sooners look to life without superstar Buddy Hield and his sidekicks, it's clear their unseasoned players will need to grow up fast.
The Central Intercollegiate Athletic Association says it won't move its headquarters, its basketball tournament or other conference championships from North Carolina, despite