Detecting Polyps in the Intestine
Colorectal polyps may be felt during digital examination of the rectum in some patients. In the event of minor blood loss (bleeding polyp), a fecal occult blood test may confirm a the presence of blood in the stool. This is, however, non-specific for intestinal polyps and other causes of blood in the stool need to be considered.
The more accurate investigations for diagnosing intestinal polyps includes double-contrast barium radiography, flexible sigmoidoscopy and endoscopy (colonoscopy).
- Flexible sigmoidoscopy, which allows visualization of the sigmoid colon, is a useful investigation for screening for colorectal polyps and can detect 50 to 60% of polyps.
- Endoscopy is the most preferred tool for accurately diagnosing colorectal polyps as it allows simultaneous visualization and biopsy. It also allows removal of the polyps in majority of the patients along with the diagnostic procedure.
- CT-colonography, which does not require passage of any instruments through intestinal tract like in endoscopy, is emerging as a valuable alternative to endoscopic screening.
- Biopsy samples taken from polyps in patients with features suggestive of inherited syndromes should be tested for mutations. First-degree relatives should be screened for polyposis and genetic testing for familial syndromes should also be performed.
Treating Intestinal Polyps
Adenomatous polyps smaller than 0.5 cm are not usually treated. In individuals with limited number of polyps, the polyps are removed (polypectomy) during the endoscopy/colonoscopy.
Removal of Single or Multiple Polyps
The stalk of the pedunculated polyp is often cut with the help of a wire-loop or snare and the base is cauterized to prevent bleeding. Flat or sessile polyps may be removed by piece-meal snare polypectomy or by using a technique called as endoscopic submucosal resection (EMR). An EMR involves injecting fluid under the polyp, which helps to lift the lesion and thereby make for easier excision. The polyp may be removed surgically if endoscopic resection of the lesion is not possible. When numerous polyps are present polypectomy may not be practical and resection of the affected part of intestine is the preferred approach in such patients.
Follow Up After Surgery
Patients who have undergone adenomatous polypectomy are at increased risk for recurrence of adenomas and also at risk for colorectal adenocarcinoma. Such patients are usually followed up with colonoscopy in 3 years. Colonoscopy may be performed earlier in patients who had multiple large polyps while the same may be delayed as much as by 5 years in case of patients with less than 3 tubular adenomas of less than 1 cm size.
Surgery for Inherited Intestinal Polyps
In patients with familial polyposis syndromes total proctocolectomy (removal of rectum and colon) combined with ileostomy or anastomosis of ileum and anus is the primary treatment option. Patients with APC gene mutations having high-risk ampullary duodenal polyps may be treated with pylorus-sparing pancreaticoduodenectomy (removal of pancreas and duodenum) or pancreas-sparing duodenectomy (removal of the duodenum while retaining the pancreas). First-degree relatives of affected individuals should be screened with APC gene testing, followed by annual flexible proctosigmoidoscopy from the age of 12.
Patients with Peutz-Jeghers syndrome are closely monitored for any complications of the syndrome with regular physical and endoscopic examination. Large polyps or bleeding polyps are removed endoscopically. Juvenile polyposis syndrome patients with severe dysplastic polyps are treated with subtotal colectomy.
For HNPCC and related conditions, a wait and watch approach is usually taken with regular colonoscopic screening every 2 years from the age of 21 to the age of 40 and then yearly thereafter. Women with strong family history for HNPCC should also undergo screening for tumors of pelvic organs including endometrial biopsy.