Can a stool cancer screening show polps?

The guaiac test. For blood in stool is not specific, and a polyp could be the cause, but occult blood is an indication for endoscopy to find tha cause of the occult bleeding: polyp, hemorrhoid, divertic, cancer, ulcer, etc.
Yes if they bleed. Most of the time polyps will not bleed so stool test will be negative , screening colonoscopy will show .