Yes, that happened to me. I have had IBS-C forever, and it continued during treatment and after. In fact, with active C Diff, I don't get a lot of D. Its hard to make me have D. I get a lot of loose stool.
I used colace and miralax. I still use these products every day. As long as I use miralax, no constipation. Both are safe and are not stimulant laxatives, so you could possibly use them forever, which many folks with IBS-C do, however, you should check that with your own provider.