been told that got to have halo surgery

when to the hospital having had  banding in  april   and flexible sigmoidoscopy in may  where the  endoscopist said i had a rectal ulcer  the doctor last  week said it was scarring from the  banding which hadnt worked and the fibre diet made the  situation  worse with the hemorrhoids  and   he suggested  that  i was to  have halo surgery i  was shocked  having nether had general  anesthesia  before . I went to pre admin  straight away  had tests etc and was told that i could be in within 5-6 weeks as the surgeon on his notes says needs doing soon as  they said it was a day case but  because im having flexible sigmoidoscopy the same time and he also said if its big enough he might cut them out  i could be in over night especialy if its afternoon surgery . just wondering what to expect heard mixed  reviews on pain to expect .