Kimb, Welcome to Healing Well
I have not taken Librax but I have heard good things about
it. Librax is a mixture of a benzo and an antispasmodic. Benzos are anti-anxiety medications which are good when your IBS is caused or worse with anxiety and the antispasmodic helps relieve the intense spasms in your intestines which is what normally causes the cramping. Please let us know how it works for you.
P.S. There is a website called askapatient.com where you can review others experiences with medications to see what others think.