Hello. My Great GrandMother would give my sister catnip & fennel when she got colic. It worked within 20 minutes. Hopefully this will help with gas relief.
I know this is gonna sound daft, but has your doc considered that you may have an impacted colon? I too thought I had IBS D for years - lots of small, loose, and watery stools each day. After a routine x-ray in the GI's office, I was told I was literally F.O.S! He explained that when the gut is impacted with waste, undigested fecal matter will squeeze around the blockage and come out before it's had a chance to undergo the full digestive process of moisture extraction and stool formation. So all those years that I thought I was going too much, I was actually not going enough. Have you had any belly x-rays done?