In elective cases, the colon is cleaned before the surgery with enemas and medication.

Bowel resection is performed while the patient is under general anesthesia (unconscious and pain-free). An incision is made in the abdomen. The diseased part of the large intestine is removed and the two healthy ends are sewn back together (resected). The abdominal incision is closed. If the entire colon and rectum is removed, it is called a proctocolectomy.

A bowel resection may be performed as a traditional "open" procedure or as a mimimally invasive laparoscopic procedure.

If it is necessary to spare the colon from its normal digestive work while it heals, a temporary opening of the colon through the abdominal wall (colostomy) may be created. The end of the healthy bowel tissue nearer to the small intestine is then passed through the abdominal wall, and the edges are stitched to the skin of the abdominal wall. An adhesive drainage bag (stoma appliance) is placed around the opening.

In most cases, depending on the disease process being treated, the colostomy is temporary and can be closed with another operation at a later date. If a large portion of the bowel is removed, the colostomy may be permanent.

The large intestine absorbs a significant amount of water from digested food. When the colon is bypassed by a colostomy, the patient should expect loose or liquid stool (feces) from the colostomy. Careful skin care and a well-fitting colostomy bag are necessary to reduce skin irritation around the colostomy.

Large bowel (colon) resection is recommended for a variety of disease processes. The most common reasons include the following:

• Cancer
• Diverticular disease
• Blockage of the intestine (intestinal obstruction) due to scar tissue

Other reasons to perform bowel resection include the following:

• Ulcerative colitis refractory to medical therapy
• Traumatic injuries
• Precancerous polyps
• Familial polyposis

Risks for any anesthesia include the following:

• Reactions to medications
• Problems breathing

Risks for any surgery include the following:

• Bleeding
• Infection

Additional risks include the following:

• Bulging through the incision (incisional hernia)
• Narrowing (stricture) of the stoma
• Blockage of the intestine from scar tissue
• Leakage from the reconnection of the intestine

Some cases may result in the permanent need for a colostomy bag.

Most patients will stay in the hospital for 5 to 7 days. Complete recovery from surgery may take 2 months. During the first few days after surgery, eating is restricted.

Laparascopic bowel resection for colon cancer may result in a faster recovery time than traditional open surgery.