Starts With A Sudden Feeling Of Bloating In Mid-lower Abdominal

Starts with a sudden feeling of bloating in mid-lower abdominal area. Then quickly turns into a feeling of indigestion, with a feeling of tightening in mid upper chest and into back of throat, with belching. Also accompanied by lightheadedness and feeling of weakness. Once it starts it will usually last several hours. Not as bad if I am not physically active, but worse if I am. Have had these episodes for 20 years at varying times with no apparent rhyme or reason as to what brings it on.