Had 3 days of pooping blood. went to hospital diagnosed with colitis. why do i still need colonoscopy?i am age 34

Colonoscopy : Colonoscopies are typically done for a variety of reasons, including diagnosis and management of inflammatory bowel conditions (IBD: Chron’s or Ulcerative Colitis), to help rule out colon cancer, and to remove polyps, some of which can lead to colon cancer. These are also conditions that can cause rectal bleeding as well and are important to identify and treat appropriately.