What you describe suggests you may have Ulcerative Colitis or Crohn's Disease. Definitely need to have that colonoscopy to confirm or rule this out. Both these conditions are treatable but cannot be ignored.

It happens. When my son was in high school he got lost on a 5k road race he was projected to to win (his HS team was running it as a warmup to the season) There was a D1 college runner that ran only the first 2 miles at a 4 1/2 minute mile pace. The golf cart leading the race stayed ahead of him. My son lost sight of them on some of the side street turns and ran 400 meters out of his way before people directed him back onto the course. He came in 6th. Others were happy to share similar stories with him when they found out.