How can someone tell the difference between gallbladder attack/ disease than acid reflux?

By character of pain. Gallbladder "attacks" are usually related to gallstones that block the excretion of bile from the gallbladder. The pain is usually shortly after meals, worse with fatty foods, and lasts about an hour or so, right upper abdomen sometimes radiating to back. Gerd, or gastroesophageal reflux, is heartburn, worse after eating spicy foods, worse when lying down after big meals at night. Antacids help.