Polyps further multiply by growing additional stolons, branches and then polyps, to form colonial hydroids. Nasal polyps (NP) are noncancerous growths within the nose or sinuses. Excisional biopsies of skin lesions and gastrointestinal polyps are very common. Chronic sinusitis occurs when one or more nasal polyps appear. Chronic rhinitis associated with polyps in the nasal cavity. Other methods of screening for polyps and cancers include fecal occult blood testing. Scyphozoans generally have planula larvae that develop into sessile polyps. CAD is available for detection of colorectal polyps in the colon in CT colonography. Most coral reefs are built from stony corals, whose polyps cluster in groups. The most prominent symptoms of nasal polyps result blockage of the nasal passage. For most of their life corals are sessile animals of colonies of genetically identical polyps. For individuals with few juvenile polyps, patients should undergo endoscopic polypectomy. The polyps of stony corals have six-fold symmetry. However, most species feed on coral polyps and sea anemones. Anosmia can also be caused by nasal polyps.