kissing gourami disease?

Question
I have a pink kissing gourami who we rescued from a local pet store about a year ago, after he got into a nasty lip-lock with another fish and was so injured nobody would take him....except for us; So I have a special soft spot for "Pinky". I have noticed recently that his lips seem to be injured every once in a while. They appear to be bloodied, and even sometimes ripped. The little opening into his mouth seems to swell closed slightly with the injury, and he gets a large blister-looking type swell above his upper lip. This seems to be present for a few days, then it clears up, and then he seems to be injured again. I guess what I'm really wondering is if this is some sort of disease or if he is getting into fights at night with my Oscar and my Red-Bellied Pacu. They all get along during the day and every one of them does their own thing, which makes me question the plausibility of the fighting scenario. He does seem to be eating and acting normally, although it sure looks like it must hurt! I woudl really appreciate your expertise!!!

Answer
I do not have any experience with Kissing Gouramis.  I don't think they are suitable companions for Oscars.  There is a chance they are fighting.  The only way to find out if that is the case is to separate them.  If he/she is not showing any other signs of illness and is eating fine, then I wouldn't suggest medicating him.  I recently had strange injuries appear on my Sparkling gourami.  It turned out a male Glow light Danio was trying to breed with the Gourami.  Once they were separated, the gourami was fine.

 If the problem continues, then look into the possibility that is fungus.  Anabantids are prone to fungus, but they usually have some behavior change and signs of stress.