Many on this board would recomend ozone. Personally, I don't have any experience with ozone. But this is the first thing that comes to my mind. Particularly since getting ozone to the stomach shoudl be quite easy.
On top of that, I recomend that you consider hyperthermia. You need access to a dry sauna. The goal is to get mom's body temperature between 104 & 105. Google "hyperthermia cancer" and you will get some great links.
Recent research has shown that stomach cancer arises from bacteria-induced inflamation. Bone marrow stem cells are at the root. Feverfew has been shown to be effective in killing malignant stem cells, and they are really small tablets, easy to swallow.
You also might want to consider some alternative clinics. Where are you located, and is your mom able to move/travel?