Anal fissure--does bleeding come and go?

Maybe, but...: Bleeding per rectum may originate in the anal canal, the rectum, or further up the line. Frequent anal sources of bleeding include hemorrhoids & fissures, that may respond to modifying stool texture (fiber, softeners) and topical agents, or require further intervention. Similar bleeds can be seen with anal & rectal cancer, infections, ischemic colitis, diverticular bleeds, inflammatory bowel, etc.