What Is a Colon Resection?

What is a colon resection?

Colon resection surgery (colectomy) removes a length of intestine that is diseased or dead, and then re-connects the severed ends to each other or to an ostomy in the abdomen attached to a colostomy bag to catch feces..

Colon resection (colectomy) is the surgical removal of part or all of the colon. The surgeon removes the diseased part of the colon and connects the remaining healthy parts (anastomosis). 

A colon resection may be performed as an 

• Open resection: conventional surgery with a single, long incision.
• Laparoscopic resection: minimally invasive, with two or four tiny incisions using surgical tools through a flexible tube with a lighted camera (laparoscope).
• Robot-assisted laparoscopic resection: laparoscopic surgery with tiny surgical tools attached to robots controlled by the surgeon.

Colon resection for certain rectal cancers may include removal of the nearby lymph nodes.

After some colectomies, the doctor may also perform a colostomy. Colostomy is a procedure where the surgeon makes an opening in the stomach wall (stoma) and attaches a bag to the open end of the colon. The feces will collect in the bag instead of being excreted normally.

The colostomy may be performed when, 

• there is a healing problem in the resected colon
• not enough healthy colon is left
• the rectum and anus are removed

Colostomy may be a temporary procedure that is reversed after about 12 weeks, or permanent in some patients.

What is the colon?

The colon, also known as the large intestine or large bowel, is the final part of the digestive system. The colon reabsorbs the fluids and nutrients from the gastric contents, and processes the waste, to be excreted via the rectum and anus.

The colon consists of

• The cecum is the beginning part of the colon in the bottom right abdomen receives the digested food from ileum, the final part of the small intestine.
• The ascending colon in the right side of the abdomen pushes the bowel contents up from the cecum to the transverse colon while absorbing the remaining fluids and nutrients in the contents.
• The transverse colon pushes the digested matter across the abdomen from the ascending to the descending colon.
• The descending colon in the left side of the abdomen receives the contents from the transverse colon and further processes the waste to form stools (feces).
• The Sigmoid colon is the terminal part of the colon which stores the fecal matter received from the descending colon till it is emptied into the rectum and passed out of the anus.

What are the types of colon resection?

Colon resection may be partial or whole. Following are the types of colectomy:

• Total colectomy: removal of the entire colon.
• Subtotal colectomy: removal of most of the colon.
• Segmental colectomy: removal of a segment of the colon
• Hemicolectomy: removal of the right or left half of the colon.
• Proctocolectomy: removal of rectum in addition to the colon.
• Low anterior resection: removal of sigmoid colon and upper rectum.
• Abdominoperineal resection: removal of sigmoid colon, rectum and anus.
• Proctectomy: removal of the rectum.

Why would you have a colon resection?

A colon resection is performed to treat and prevent diseases of the colon. It is usually considered after less invasive methods have failed to provide relief to the patient. It may be performed as an emergency procedure for certain acute conditions such as major hemorrhage and perforation to the bowel.

A doctor may perform a colon resection for the following conditions:

• Colorectal cancers such as
  • Cecum and ascending colon cancer
  • Transverse colon cancer
  • Descending colon cancer
  • Sigmoid cancer
  • Rectal cancer
• Diverticular (pouches in the colon) diseases of the colon
  • Diverticulosis with massive hemorrhage
  • Diverticulitis (perforation of diverticular pouches) with complications such as obstruction or abscess
• Trauma and perforation to the colon through injury
• Severe gastrointestinal bleeding
• Inflammatory bowel diseases such as
  • Ulcerative colitis
  • Crohn’s disease
• Bowel infarction (irreversible injury to the bowel due to insufficient blood supply)
• Colonic inertia (slow-rate constipation)
• Intussusception (a part of the bowel telescoping into another)
• Twisting of the bowel
• Blockage in the colon due to scar tissue from previous surgery
• Neurogenic bowel dysfunction (loss of bowel function due to nerve problems)

Colon resection may be done as a treatment or a precautionary measure in people with inherited conditions that predispose them to developing precancerous polyps or being at high risk for colorectal cancer.

• Familial adenomatous polyposis: development at a young age of hundreds to thousands of premalignant polyps that turn into cancer later.
• Hereditary nonpolyposis colorectal cancer: a genetic condition with high risk of colorectal cancer without development of many polyps.