title: Colonic transit in the empty colon after defunctioning ileostomy: do we really know what happens?
abstract: BACKGROUND
  There is disagreement amongst surgeons about the use of oral mechanical bowel preparation (MBP) prior to low anterior resection with diverting ileostomy. Colonic transit in the early post-operative period is an important factor in determining the role of MBP, as propagation of any stool remaining in the defunctioned colon may exacerbate morbidity in the event of anastomotic leak. We studied colonic transit time in the first 7 days following low anterior resection with diverting ileostomy.
  
  
  METHODS
  We conducted a prospective observational study of patients with rectal cancer undergoing elective low anterior resection with diverting ileostomy in a tertiary colorectal unit. Twenty radio-opaque markers were inserted into the caecum via the distal limb of the loop ileostomy at surgery. Plain abdominal radiographs were taken on post-operative days 1, 3 and 5. The primary endpoint was passage of the markers to the neorectum. Data were collected on treatment, return of gastrointestinal function and complications.
  
  
  RESULTS
  Twenty-two patients (mean age 68.5 years; 18 males) participated in the study. In 20 patients, all markers remained in the right colon on day 7. Three markers were present in the left colon in one patient, and eight markers were present in the neorectum in another patient, on the seventh day.
  
  
  CONCLUSIONS
  Colonic transit may be abolished by the presence of diverting ileostomy. It should now be established whether clearance of the left colon alone, using enemas, is sufficient for patients undergoing low anterior resection, thus avoiding the morbidity associated with oral MBP.
authors.affiliation: Cambridge Colorectal Unit, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, BOX 201, Hills Road, Cambridge, CB2 0QQ, UK, ja297@cam.ac.uk.
authors.forename: J M
authors.initials: JM
authors.lastname: Ali
authors.forename: S G
authors.initials: SG
authors.lastname: Rajaratnam
authors.forename: S
authors.initials: S
authors.lastname: Upponi
authors.forename: N R
authors.initials: NR
authors.lastname: Hall
authors.forename: N S
authors.initials: NS
authors.lastname: Fearnhead
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002432:Cecum / Q000503:physiopathology; D003106:Colon / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D057918:Fiducial Markers; D005772:Gastrointestinal Transit / Q000502:physiology*; D006801:Humans; D007081:Ileostomy / Q000009:adverse effects* / Q000379:methods; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D011860:Radiography, Abdominal; D012004:Rectal Neoplasms / Q000503:physiopathology* / Q000601:surgery; D012007:Rectum / Q000503:physiopathology / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome