A stoma is a surgically created opening in the body between the skin and a hollow viscus (stoma has the Greek meaning ‘mouth). Abdominal stomas are mainly used to divert faeces or urine outside the body where it can then be collected in a bag on the skin.
There are three common stoma types:
Each stoma can be either permanent or temporary.
A stoma’s position, appearance and contents can indicate which type of stoma it is and provide clues as to the patient’s previous surgical history.
As the name suggests, colostomies are made using the large bowel (or colon).
One of the hallmarks of colostomies is that they are found in the left iliac fossa (LIF).
The contents of a colostomy bag should be solid as the faeces have had time to travel through the colon undergoing water absorption.
Colostomies are positioned flush to the skin(i.e. no spout) because the enzymes present in large bowel contents are less alkali and, therefore, less irritating to the skin.
Permanent end-colostomy vs temporary end-colostomy
Permanent end-colostomies are often performed in cases of abdominoperineal resection of large rectal cancers leading to the removal of the entire rectum.
Temporary end-colostomies are sometimes performed to allow the distal bowel to rest in the context of acute diverticulitis or obstruction. In a two-stage Hartmann’s procedure, the rectum and bowel are re-anastomosed at a later date, once any acute inflammation has settled.
Loop colostomies areperformed to protect distal anastomoses after recent surgery.
A loop of bowel will be brought to the skin’s surface and half-opened, this allows the faecal matter to drain into the stoma bag without reaching the distal anastomoses.
Ileostomies are created using small bowel and are typically located in the right iliac fossa (RIF).
Less water is absorbed in the small bowel, so the contents of the stoma bag tend to have a liquid consistency.
Because the enzymes contained in small bowel contents can irritate the skin, the bowel 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 typically created after a panproctocolectomy for conditions such as ulcerative colitis or familial adenomatous polyposis.
A temporary end-ileostomy is typically created during 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 created in the same way that temporary loop colostomies are, with two openings being visible.
They are used to protect distal anastomoses.
Urostomies after created after a cystectomy (bladder removal) and are typically located in the right iliac fossa (RIF).
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 bowel.
The urine then drains via the piece of ileum into the stoma bag.
Cancer Research UK. Licence: CC BY-SA. Available from: [LINK]