My mother had severe GERD and was told she had hyperacidity. The thing is hyperacidity is rarely the cause of reflux. She actually had very low stomach acid and now takes betaine HCL with pepsin and digestive enzyme supplements with great results.
Excerpt from Chris Kresser's article "Get rid of heartburn and GERD forever in three simple steps"...
"To review, heartburn and GERD are not caused by too much stomach acid. They are caused by too little stomach acid and bacterial overgrowth in the stomach and intestines. Therefore successful treatment is based on restoring adequate stomach acid production and eliminating bacterial overgrowth.
This can be accomplished by following the “three Rs” of treating heartburn and GERD naturally:
1. Reduce factors that promote bacterial overgrowth and low stomach acid.
2. Replace stomach acid, enzymes and nutrients that aid digestion and are necessary for health.
3. Restore beneficial bacteria and a healthy mucosal lining in the gut. Reduce factors that promote bacterial overgrowth and low stomach acid
As we saw in Part II and Part III, a high carbohydrate diet promotes bacterial overgrowth. Bacterial overgrowth – in particular H. pylori – can suppress stomach acid. This creates a vicious cycle where bacterial overgrowth and low stomach acid reinforce each other in a continuous decline of digestive function.
It follows, then, that a low-carb (LC) diet would reduce bacterial overgrowth. To my knowledge there have only been two small studies done to test this hypothesis. The results in both studies were overwhelmingly positive."
No pain but she didn't have bacterial overgrowth in her intestinal tract. You can try probiotics (good bacteria) to see if the pain goes away. If symptoms persist see another doctor.
Is the pain in the upper or lower abdomen? I forgot about my mother's gastritis pain (upper left abdomen). Digestive enzymes heal the stomach lining although this takes time to heal.
I remember my mother saying she had pain radiating to her back as well with gastritis.
I found an article from American Family Physician - Evaluation of Acute Abdominal Pain in Adults with this list of causes for LUQ pain...
"Left upper quadrant
Cardiac: angina, myocardial infarction, pericarditis
Gastric: esophagitis, gastritis, peptic ulcer
Pancreatic: mass, pancreatitis
Renal: nephrolithiasis, pyelonephritis
Vascular: aortic dissection, mesenteric ischemia"
I hope you find what the cause is. :)