Candida doesn't cause IBS. That is really bad information on Bee's site about IBS.
Remember IBS is a specific entity, basically of the sigmoid colon.
Gas and bloating are common IBS symptoms.
Part of the problem in IBS are the nerves are hypersensitive in the gut to stimulous and the gas even normal gas creates problems because of transit problems in IBS.
Expert Commentary – Bloating, Distension, and the Irritable Bowel Syndrome