I know of someone with episodes of acidic taste at night (especially after having oat cereal in milk) where bits of cereal and sometimes rice was found in the mouth.
Then had gastric-like feeling in the stomach. The gastric symptoms appeared after a stressful and busy period at work where meal times were also inconsistent.

GP prescribed omeprazole which magically cured the gastric symptoms. It was supposed to be for just a few weeks but unfortunately gastric attack would come 24hours after the last omeprazole was taken.

A specialist did endoscopy and saw that patient has hiatus/hiatal hernia which contributes to the "backflow" of food bits and stomach juice. Patient was advised to lose weight as it would help due to less stomach fat exerting pressure on the esophagus.
Specialist said that the hernia and gastric attacks were not related, and stress is one of the main contributors of gastric attacks where the stomach produces more acid to digest food in order to provide energy.

The patient then tried to wean off omeprazole by:
1. taking probiotics (apparently, high stomach acid content will harm these little fellows)
2. having small meals and having food like biscuits on standby so that he does not go hungry.
3. chewing gums, which apparently helps to produce saliva which is supposed to be beneficial for him.
4. changing job (yes, to one that is less stressful albeit lower paying).
5. increasing physical activity and reducing weight.

He has stopped taking omeprazole for more than a year with only very isolated cases of minor discomfort, if at all. Of course, spicy food is out, or there will be discomfort.