Dawn, Asacol is an anti-inflammatory, so I doubt very much that the symptoms you've described are related to this drug. However, the symptoms do seem a lot like some of the extra-intestinal symptoms common in IBD.
Has your husband been sharing the joint issues with his doctor? It might be a good idea for your husband to be reassessed by his GI doc. Asacol (mesalamine) doesn't help everyone, and stopping the Asacol probably didn't have anything to do with the joint symptoms going away at that particular time; IBD flares tend to come and go rather mysteriously, it seems.
My best to your husband,
Hope