The midfielder was stretchered off after eight minutes of treatment on the pitch following a second-half clash of heads with Bristol City defender Damion Stewart.
Visiting boss Paul Jewell said: "Grant has been taken straight to hospital suffering from concussion. He was unconscious when our medical staff reached him on the pitch, but seemed okay by the time he got back to the dressing room.
"We are hoping it's not a serious injury."
A 30-yard strike from 17-year-old Josh Carson on 52 minutes took former England goalkeeper David James by surprise and nestled in the bottom corner to give Ipswich the points.
Source: PA
Source: PA