Intestinal stoma is often required during treatment of rectal cancer and sometimes for colon cancer. The stoma is either permanent or temporary. Stoma is also constructed for temporary relief of distal anastomosis or ileus.
Permanent stoma is prepared when the rectum is removed or when there is an inoperable tumor or ileus due to extreme adherences. Preferably, it is placed as close to the anus as possible to provide the best possible reabsorption of nutrition and fluid.
The procedure may be performed by laparoscopy.
A stoma can have with one or two openings. The type of stoma depends on the purpose of the stoma and anatomical conditions in the abdomen.
End stoma 
The colon is divided and the oral end is brought out. The end stoma is easier to handle and is better looking than a loop stoma. The end stoma is usually performed for permanent stomas and for relief of fistulas.
Loop stoma
The colon is not divided but is pulled out like a loop through the abdominal wall. An opening is made in the top of the loop. The stoma has two openings: one oral and one aboral. The stoma can be prepared in two ways:
- symmetrical—an opening is made on the top of the extracted "backwards U." The ingoing and outgoing openings of the bowel looks similar. Symmetric loop stoma are usually performed for colostomy .
- asymmetrical—the oral part of the bowel is brought forward and empties easier into the bag while the aboral part of the bowel is at the skin level and the opening is small. Asymmetric loop stoma is usually created for an ileostomy .
Sigmoid colostomy
Sigmoid colostomy is the most common form of colostomy. The stoma is installed if it is not technically possible or sensible to anastomose the colon to the rectum/anal canal. It is then constructed as a permanent end stoma. This is done in 15-30% of patients with rectal cancer.
Indications
Permanent:
- for rectal amputation
- to avoid permanent incontinence of poor anal sphincter function (Hartmann's operation)
- to relieve an inoperable fistula anally from the stoma
Temporary:
- for preoperative radiation
- relief of rectal ileus
Sigmoid colostomies are easy to maintain. The stools usually has a normal consistency and causes little irritation to the skin.
Transverse colostomy
The transverse colon is brought out in the right rectus muscle. This is a loop stoma and is often temporary. It is often difficult to maintain because the stoma is voluminous and the feces is thin and foul-smelling. This type of stoma is associated with more complications than a sigmoidostomy. As a temporary stoma it has similar frequency of complications as ileostomas.
There is a risk that the bowel content may pass into the distal opening with an incomplete relief of stools.
Indications
- relieve stenosis in the left colon
- relieve low anastomosis or rectum resection
- allow rinsing of the left colon through the stoma in limited anastomosis leakage
Ileostomy
The ileum is brought out 20-30 cm from the cecum and preferably in the right rectus muscle as an asymmetrical loop stoma. It is relatively simple to construct but can be difficult to maintain due to thin fecal content. The longer nipple will help avoiding damage to the skin.
Indications
- protect anastomoses after rectosigmoid resection
- relieve bowel obstruction
- relieve preoperative radiation of stenosis due to colorectal cancer
- relieve fistula
Indications for stomas
- Cancer in the rectum (rectum amputation, Hartmann)
- Cancer in the colon
Goals
- Facilitate output of bowel contents
- Relieve the bowel/stenosis/fistula