Are IBS and GERD the same thing?

No but. They can co-exist. Gerd is acid reflux into the esophagus from the stomach. Ibs is characterized by abdominal bloating and alternating diarrhea or constipation to varying degrees, and abdominal cramping.
No. Ibs is "irritable bowel syndrome" and effects the intestines usually causing bouts of diarrhea and constipation along with cramping and bloating. Gerd is "gastroesophageal reflux disease" or simply "reflux." acid from the stomach refluxes into the esophagus and throat causing an uncomfortable, burning sensation. It is usually due to an imcompetent sphincter muscle between the esophagus & stomach.