A sessile polyp is a type of colon polyp that grows flatly inside the colon wall, and it does not have a stalk, according to WebMD. Sessile polyps can be cancerous and must be removed when detected during sigmoidoscopy or colonoscopy.
Colon polyps grow in the colon or rectum, some of which may cause rectal bleeding or cancer depending on type and size, according to WebMD. A sessile polyp, which is directly attached to the colon wall, may expand its base as it grows. Benign sessile colon polyps can be detached through colonoscopic excision; however, laparotomy is necessary for all cancerous sessile lesions, according to PubMed.gov.