Patient Timing (wks) Imaging ISGRC group Details 1 38 GGE A Small leak with pre-sacral cavity on routine GG enema 2 14 GGE A Small leak with pre-sacral cavity on routine GG enema 3 29 CT + clinical A Pre-sacral collection and palpable anastomotic defect 4 8 GGE + clinical A Small anastomotic defect palpable - confirmed on GGE 5 2 GGE + clinical A Small anastomotic defect palpable - confirmed on GGE 6 6 MR B Re-admission with pelvic abscess drained transrectally 7 8 GGE A Small leak with pre-sacral cavity on routine GG enema 8 1 CT B Pelvic collection - percutaneous + subsequent transrectal drain* 9 <1 CT + clinical A Faeculant initial drain output - small leak on subsequent GGE 10 2 CT B Concurrent leak and pancreatic fistula - died 9wks post-op 11 33 GGE A Small leak with pre-sacral cavity on routine GG enema 12 1 CT A Small pelvic collection - recto-vaginal fistula 7 months post-op 13 12 GGE A Pre-sacral collection and palpable anastomotic defect

Table 2: Details of anastomotic leaks (n=13). GGE=Gastrograffin Enema/ISGRC=International Study Group of Rectal Cancer (A=no active therapeutic intervention/B=active therapeutic intervention but managed without re-laparotomy/C=re-laparotomy required). *Patient went on to develop anastomotic stricture eventually requiring reversal of loop ileostomy and formation of permanent end colostomy 20 months following initial resection.