Last updated: 02/17/2009

Diagnostic tests

A number of tests identify masses and perforations within the intestinal tract.

• A lower GI (gastrointestinal) series is a series of x rays of the colon and rectum that can help identify ulcers, cysts, polyps,...
  
  diverticuli (pouches in the intestine), and cancer. The patient is given a barium enema to coat the intestinal tract, making disease easier to see on the x rays.
• Flexible sigmoidoscopy involves insertion of a sigmoidoscope, a flexible tube with a miniature camera, into the rectum to examine the lining of the rectum and the sigmoid colon, the last third of the intestinal tract. The sigmoidoscope can also remove polyps or tissue for biopsy.
• A colonoscopy is similar to the flexible sigmoidoscopy, except the flexible tube examines the entire intestinal tract.
• Magnetic resonance imaging (MRI), used both prior to and during surgery, allows physicians to determine the precise margins for the resection, so that all of the diseased tissue can be removed. This also identifies patients who could most benefit from adjuvant therapy such as chemotherapy or radiation.

Preoperative preparation

To cleanse the bowel, the patient may be placed on a restricted diet for several days before surgery, then placed on a liquid diet the day before, with nothing by mouth after midnight. A series of enemas and/or oral preparations (GoLytely, Colyte, or senna) may be ordered to empty the bowel. Oral anti-infectives (neomycin, erythromycin, or kanamycin sulfate) may be ordered to decrease bacteria in the intestine and help prevent post-operative infection. The operation can be done with an abdominal incision (laparotomy) or using minimally invasive techniques with small tubes to allow insertion of the operating instruments (laparoscopy).