I would talk to your veterinarian about changing your cat's diet. By switching her slowly to canned food you can increase her water intake in her food which should help the dryness of the stool. There may be too much fiber for her in the R/D which is triggering the frequent defecation. There are other effective low calorie food such as Royal Canin Calorie Control and Purina OM. Ask your vet which diet would be best and have him/her calculate calories for your cat based on a canned or canned and dry diet.
Judy Karnia, DVM
Scottsdale Cat Clinic