What can I do for constipation?

I am a 43 year old woman with IBS. Usually my tummy does pretty good, or I should say normal BM’s. Lately not so good. I go from severe constipation for 4 days or so, to severe diarrhea for 2 or 3 days. This has been going on for about 3 weeks now. Currently I have gone 6 days with no BM. I have tried Phillips M.O.M., drinks lots of water, and OTC enemas and stool softeners. No relief and I am miserable. Any suggestions?