End colostomy (sigmoid/descending colon): proximal bowel opening brought to surface and distal bowel removed or stapled off/oversewn. Uses include:
Abdominoperineal (AP) resection for low rectal tumours (all distal bowel removed so permanent colostomy required)
Hartmann’s procedure for emergency resection of rectosigmoid lesions where primary anastomosis is unfavourable due to obstruction/inflammation/contamination (proximal bowel made into end colostomy and distal bowel stapled off/oversewn – may be reversed after inflammation settled)
Loop colostomy (transverse/descending colon): two openings made in a loop of intact bowel that is brought to the surface through one incision to form a stoma. The proximal opening drains faeces and the distal opening can drain mucus. It may be initially supported by a plastic rod. It is most commonly performed to divert the faecal stream away from distal bowel because of:
Impending or actually obstructed large bowel
Colonic lesions where the patient may not survive extensive surgery but still maintains a certain quality of life (such as contained tumour perforations or fistulae)
A distal bowel resection with primary anastomosis (to protect the anastomosis while sutures heal; reversed after around 6 weeks) – however, loop ileostomies are now more commonly used for this indication
Double barrel colostomy (transverse/descending colon): a segment of bowel removed and both ends brought to the surface separately to form a stoma. The proximal end drains faeces and the distal end (called a ‘mucous fistula’) can drain mucus from the non-functioning bowel. Used infrequently after a segment of colon removed and primary anastomosis is unfavourable.
Ileostomy
End ileostomy (terminal ileum): previously, a permanent ileostomy was required when the whole colon and anus were removed in a panproctocolectomy (e.g. for ulcerative colitis, familial adenomatous polyposis, Hirschsprung’s disease). However, newer sphincter-saving procedures allow ileoanal anastomosis so this is now less commonly performed. End ileostomies may still be created with subtotal colectomies (e.g. for toxic megacolon, ischaemic bowel or synchronous tumours) and may be reversible.
Loop ileostomy (distal ileum): as loop colostomy. Commonly used to protect ileoanal or low colorectal anastomoses, or to prevent stool passing through anorectum (e.g. in perianal Crohn’s disease, anorectal trauma or malignancy).
Urostomy
Ileal conduit: short segment of ileum removed to act as bladder. One end sutured to skin, other end sutured to ureters. Replaces bladder after cystectomy (for bladder carcinoma).