What is a stoma?
A stoma is a surgically created opening in the body between the skin and a hollow viscus (stoma is Greek meaning ‘mouth). Abdominal stomas are mainly used to divert faeces or urine outside the body where it can be collected in a bag at the skin.
Stomas fall into 3 types:
Each stoma can also be either permanent or temporary.
A stoma’s position, appearance and contents can point to which type of stoma it is and provide clues as to the patient’s previous surgical history.
As the name suggests these stomas involve the large bowel (or colon).
One of the hallmarks of colostomies is that they are found in the LIF.
The content of a colostomy bag should be solid as the faeces have had time to travel through the colon undergoing water absorption.
Colostomies can also be identified because they will be flush to the skin, not sticking out like ileostomies. This is because the enzymes are less alkali so should not damage the skin.
Permanent end colostomy vs temporary end colostomy
You cannot differentiate between permanent end colostomies and temporary end colostomies clinically, so in this case you’d have to ask the patient or check the notes.
- Permanent end colostomies are often done in cases of abdominoperineal resection of large rectal cancers leading to the removal of the entire rectum.
- Temporary end colostomies are done to rest the bowel such as in diverticulitis or obstruction by a tumour. As part of a two stage Hartmann’s procedure the rectum and bowel will be re-anastomosed at a later date.
Loop colostomies are done to protect distal anastomoses after recent surgery. A loop of bowel will be brought to the surface and half opened, this allows the faecal matter to drain into the stoma bag without reaching the distal anastomoses, a supporting rod is used to secure the two parts to the skin. The two parts are still attached as this is a temporary procedure which will be reversed.
Formed of small bowel.
Usually located in the right iliac fossa (RIF).
Not as much water absorbed in the small bowel so the contents of the stoma bag are liquid and lighter.
Because the enzymes in the faeces are toxic to the skin the bowel is not secured flush to the skin but has a spout sticking out from the abdominal wall. This allows faeces to drain without touching the skin.
Temporary vs permanent end ileostomy
Permanent ileostomies are done after a panproctocolectomy for ulcerative colitis or familial adenomatous polyposis.
Once again a temporary end ileostomy cannot be distinguished from a permanent end ileostomy but is used instead in emergency bowel resection where it is considered unsafe to form an anastomosis with the remaining bowel at that time (e.g. intra-abdominal sepsis or bleeding).
Temporary loop ileostomies are done in the same way as in temporary loop colostomies, so you will see two openings instead of one but they will be connected and are used to protect distal anastomoses.
Used after a cystectomy (bladder removal).
Located in right iliac fossa (RIF).
Bag contains urine not faces, this is the only way to differentiate from ileostomy.
An ileal conduit is used to route the urine out of the abdomen into the bag. This involves a piece of ileum being resected then attached to the skin with a spout protruding. The ureters are then attached to the other end of the tube of bowel. The urine then drains via the piece of bowel into the stoma bag.
1. Flesh and bones of surgery – page 58-59, 2007
2. 2nd edition essential examination – page 104-106, 2010
3. Colostomy image – (https://en.wikipedia.org/wiki/Colostomy – By Cancer Research UK)
4. Loop colostomy image – (http://www.cancer.org/treatment/treatmentsandsideeffects/physicalsideeffects/ostomies/colostomyguide/colostomy-types-of-colostomies)
5. Ileostomy image – (https://commons.wikimedia.org/wiki/File%3AIleostomy001.jpg – By Remedios44 – GFDL)