Howdy,
The CD that came with "Two Confederate Hospitals and Their Patients, Atlanta to Opelika", by Jack D. Welsh list the names (mostly initials for first and middle)of the soldiers that were admitted to the Fairground Hospitals No. 1 and 2 in Atlanta, and their disposition. Most have their unit and cause for admission.
If you want me to see if your ancestor is listed send his name, unit (if known), etc.
Bobby