Did they check your potassium level cause those are all the symptoms of a severly low potassium level
Damn....better make sure it is IBS and not an inflammatory bowel disease. Try cutting out grains and dairy for a while, and take a really good probiotic.I have really bad idiopathic constipation but was originally diagnosed with IBS and found the above to help. Also maybe they should do some imaging studies?
Have you seen a GI doctor yet? If not, make an appt. to see one since they are specialists in this area. The medication you were given is an older medication and there are newer ones available now that the GI doctor can prescribe. Get copies of your reports from the testing that was just done, labs, anything you can to send over to the GI doctor.
In the meantime while you are waiting for an appt. for the GI doctor, tell your PCP (if he/she is the one currently treating you) that the Bentyl is not working.
There are other things that you can do to help your situation. See this link to learn more: http://digestive.niddk.nih.gov/ddiseases/pubs/ibs/ . Please let us know if we can assist you more.