What nobody's mentioned is that it could be hormone related. Your wife needs to get a panel done and check her estrogen and progesterone levels and go from there.
A good probiotic is the best place to start. Take 1 first thing in the morning and another before bed, empty stomach. Digestive enzymes with 2 or 3 of the solid meal foods daily.
Try cutting the fats, if not being able to finish a meal is the problem, and if it feels like her food isnt digesting. Eating the same foods daily for a while is helpful in determining any food sensitivities. Too much variation makes it difficult to pinpoint whats doing what.
Also take a lool at her rx. Sometimes anavar is a common cause of bloat.
The simplest answers can usually be found in the food.
Did she run something before?maybe it due to side effects if yes, If she did not take any medicine, youd better consult the doctor for professional advice