CT Scan for diagnosis

Hi everyone.  I'm new here and just accidently posted on the IBS board...whoops!  Of course, I also have IBS, so maybe someone can help.  I have a CT barium contrast scan scheduled today of the abdomen.  Has anyone else experienced this?  I really think it is an ulcer or hiatal hernia...will the CT pick this up??  If this turns out to be negative, I think I will request an upper GI or Endoscopy.  Any help would be appreciated. :-)