it isn't enzymes that makes food particles smaller, it's the gastric fluids in the stomach that do that. The stomach's job is to reduce everythign to a paste called chyme. so you need to increase stomach acids. People think that burning stomach is due to too much stomach acid, but in fact if the burning happens while you eat it's due to a LACK of acids. It's only excess acids if it burns on an empty stomach. So peppermint tea, or 500 mg of vitamin C, lemon juice, HCL Betaine, will increase stomach acids.
If you DO have an ulcer currently, then increasing stomach acids will be quite painful. So there's the rub - what do you do? Well, you cleanse the bowels to make sure there's no obstruction causing a backflow, which irritates the stomach lining further, and you drink/eat mucilogious substances that coat and protect the stomach lining. Marshmallow tea/tincture, or slippery elm, will do this. Pepsin will do as well. Some people react very well to aloe vera juice. So you have to do that for several days before increasing stomach acids. Until then you should pretty much fast on juices and broths. To rebuild the stomach lining, you need L-glutamine, or a good source of easily assimable protein - raw eggs, liver, bone broths.