Red streak on one stool among several, in one sitting, occurs only once every couple weeks. In 2nd month now. Most times consistency varies from soft, light brown to occasionally hard dark brown balls, not black. Had prostate cancer treated 3 years ago with Proton therapy. Last PSA in Aug. 2017 was 1.8. Had colonoscopy in Oct 2017. Supposedly no polyps found. Also have a tag near butthole that seeps blood at rare times when sitting for extremely long periods. Looking for reassurance or else reason for concern..