Burping even after fasting for 12+ hours?

Everything I’ve been seeing online talks about bloating, gas, and burping 2-4 hours after meals. But has anyone experienced burping throughout the day regardless of last meal? I haven’t eaten anything in almost 15 hours and I’m burping. Is this a symptom of SIBO? I see my GI doctor in two weeks, have had a colonoscopy and several endoscopies. The colonoscopy came back normal but about two years ago my first endoscopy showed stomach ulcers which was “treated” with a PPI, however my most recent one in July showed nothing, but my symptoms of a light burning feeling in my throat, bloating, weight loss, abdominal pain, and feathery edged stools persist. I’m waiting for pH probe results from two weeks ago as well.