Hi Chris. It is unlikely the excess acid alone could be causing this. The parts of the gut beyond the stomach have various mechanisms to neutralize and dilute the acid or it could cause severe damage to these parts. But excess acid could irritate the first part of the small intestine (duodenum) and lead to inflammation and ulcers.

Even if the acid was not neutralized fully in the duodenum, it would be very dilute by the time it mixes with the water that is pumped into the bowels as the process of digestion continues in the lower parts of the gut. The yellow stool is more likely to be related to your bile and possibly even rapid bowel motility where there is inadequate digestion. You can read more about yellow stool in this article https://www.healthhype.com/yellow-bowel-movement-cause.html

It is difficult to say for sure. Most of the symptoms you report are issues with acid reflux and gastritis or peptic ulcer disease. You should see a gastroenterologist about these complaints. There could be other issues like inflammatory bowel disease (IBD) and so on that needs to be investigation. An upper GI endoscopy and/or colonoscopy may also be useful investigations at this point.

Hi Chris. Sorry our reply is above your comment.