Dor de estômago, dor no peito, catarro

Good afternoon,
I am searching for possible answers for my boyfriend. He is 32 year old male. Was 320 last year before everything started. It started with pressure in his stomach during work time. Went to the doctors and they took blood work, x-rays. Said everything was fine, of course he already started to loose weight. Since it was bothering him. November comes and wakes up with lots of phlegm, headaches, sore throat. It has not gone away. January comes along still experiencing all these symptoms and more. He is now having pain in his esophagus, stomach, chest pain. The doctors have no answer , only to say it is heartburn. He knows what heartburn is. He knows how bad he used to eat and how alcohol caused him heartburn. Mentions this is not the same, this is not going away. Has done multiple blood work, CT scans, X-rays, and two gastroscopy done. Only thing they find is 2cm hiatal hernia, and mild gastritis. Heavy medications to help tame gastritis that should be helping is not helping. Poor guy does not know what else to do. He also talked to doctors in Mexico and have also mentioned if it is heart burn the heavy medications that is meant for it should be helping. His doctors here are recommending gastro bypass. In which, he would do it if it was meant for weight loss and to help his situation. Mentions he does not care about loosing more weight. I mean he is now down to a size L maybe XL if that. Does not eat like he used to, has cut down a lot. Anyways his GI doctor mention he might not even need a gastro bypass. So different doctors are giving him different answers. I would hope someone here would have some experience in the same situation.
Symptoms again are. Stomach pressure, pain in the chest, stomach, throat, esophagus, stuffy nose, lots of phlegm, headaches, coughing.

If he’s using electronic cigarettes it’s time to stop. But you should know that they cause permanent damage.