DGL has a healing and anti inflammatory effect on the stomach lining. If you have ulcers or gastritis it can be of help. Aloe vera has a similar healing effect along with other digestive benefits.
Bitters and apple cider vinegar add acid to your stomach. If you feel your condition is due to low stomach acid, which it very well may be for meany heartburn sufferers, these are the proper remedies.
They are in a sense at odds with each other. If you need to heal your stomach lining, then adding more acid may not be the best thing to do. If you have heartburn, gas, bloating and reflux, and no damage to your stomach lining, additional acid may actually be the correct treatment.
You really have to know what's causing your problem before starting any treatment.