You might not be getting the proper balance of enzymes. Most survivors of pancreatic cancer take some kind of pancreatic enzyme supplement, but not all take a proteolytic enzyme supplement (protease). If you aren't getting enough of both of these types enzymes, it's very easy to have incomplete digestion of foods, and to accumulate irritation in the bowel - this can indeed cause a lot of gas, as well as just plain bowel pain.
You can try a very simple experiment using over the counter supplements to see if this might be the problem. Purchase small bottles of both papaya wafers (contains papaine) and bromelain , and some non-diet ginger ale. Take the papaya and bromelain about 20 minutes before each meal (use amounts recommended on the labels) - the papaya needs to be chewed, but just swallow the bromelain whole. Put 4 ounces of ginger ale out in a glass at the same time. letting it sit so that it will go flat, then drink the flat ginger ale with your meal. Do this routine with each meal. (This uses the ginger in the soda as a gentle boost to the other enzymes - let it go flat so the carbonation doesn't contribute to the gas.)
(I recommend you DO NOT drink a diet ginger ale - there are some very real concerns that aspartame and other artificial sweeteners have some very deleterious effects on compromised immune systems. And please do not try this experiment if you know you are allergic to papaya, pineapple, and/or ginger.)
If insufficient proteolytic enzymes is indeed the problem, you should start feeling better within 3 - 4 days.
Here's a great article that explains the role of proteolytic enzymes in fairly understandable language. Don't worry about the stuff it says about HUT fungal protease, nattokinase, aspergillus, etc. Just trying the papaya, bromelain and ginger ale should be enough to see if it's going to help, without causing any harm to your system.
If this helps, you can continue to use the papaya and bromelain supplements, and/or a ginger supplement, or you could ask your doc if he wants to put you on a more potent proteolytic enzyme preparation.
Certainly if you have any concerns about trying this, please first ask your dr if it's ok.
I hope this helps!!
Sincerely, Tre