@messygirl Your symptoms sound pretty much identical to mine, and my problem turned out to be lactose intolerance. I'm not saying you have that, but it does sound like something you eat regularly is causing this. Your best bet would be to try an elimination diet and see if that helps.
I also had little pain or discomfort, just the loose stools and very bad smelling gas. Since eliminating dairy I rarely have a problem. I had a minor one today and I think something I ate must have some lactose hidden in it. The only thing I can think of is coleslaw but I never thought that had any dairy in it. I do get a bit of help if I take Imodium. It's not perfect but it's better than anything else I have tried. Lactaid is of no help.