Stomas may be sited during a range of abdominal procedures and involve bringing the lumen or visceral contents onto the skin. In most cases, this applies to the bowel. However, other organs or their contents may be diverted in case of need.
With bowel stomas, the type method of construction and to a lesser extent the site will be determined by the contents of the bowel. In practice, small bowel stomas should be spouted so that their irritant contents are not in contact with the skin. Colonic stomas do not need to be spouted as their contents are less irritant.
In the ideal situation, the site of the stoma should be marked with the patient prior to surgery. Stoma siting is important as it will ultimately influence the ability of the patient to manage their stoma and also reduce the risk of leakage. Leakage of stoma contents and subsequent maceration of the surrounding skin can rapidly progress into a spiralling loss of control of stoma contents.
Rule of thumb:
| Ileostomy | Colostomy | |
|---|---|---|
| Location | Right iliac fossa | Varies, more likely on the left side of the abdomen |
| Appearance | Spouted | Flushed |
| Output | Liquid | Solid |
More detail:
| Name of stoma | Use | Common sites |
|---|---|---|
| Gastrostomy | • Gastric decompression or fixation | |
| • Feeding | Epigastrium | |
| Loop jejunostomy | • Seldom used as very high output | |
| • May be used following emergency laparotomy with planned early closure | Any location according to need | |
| Percutaneous jejunostomy | • Usually performed for feeding purposes and site in the proximal bowel | Usually left upper quadrant |
| Loop ileostomy | • Defunctioning of colon e.g. following rectal cancer surgery | |
| • Does not decompress colon (if ileocaecal valve competent) | Usually right iliac fossa | |
| End ilestomy | • Usually following complete excision of colon or where ileocolic anastomosis is not planned | |
| • May be used to defunction colon, but reversal is more difficult | Usually right iliac fossa | |
| End colostomy | Where a colon is diverted or resected and anastomosis is not primarily achievable or desirable | Either left or right iliac fossa |
| Loop colostomy | • To defunction a distal segment of colon | |
| • Since both lumens are present the distal lumen acts as a vent | May be located in any region of the abdomen, depending upon colonic segment used | |
| Caecostomy | Stoma of last resort where loop colostomy is not possible | Right iliac fossa |
| Mucous fistula | • To decompress a distal segment of bowel following colonic division or resection | |
| • Where closure of a distal resection margin is not safe or achievable | May be located in any region of the abdomen according to clinical need |