Anal gland impaction, abscess, and bursting was the chronic problem that preceded my dog’s surgical removal. When they would abscess and burst it was not smelly. There was some pus but mostly blood and clear serum fluid. The area would be red, very sore, and uncomfortable for her. When she developed the fistula it was like a small amount of draining from a fresh surgical site, it just never stopped. Also not smelly, mostly clear fluid. No redness, no swelling. Really no other symptoms. Would clear up for a day, maybe two, sometimes a week or 10 days and you think, great it’s healed–only to come back again, and again, and again.