You could be reacting from something you ate prior, which sometimes takes an hour or two to manifest, and coincidently, you’re handling food at the time it strikes.
Smelling food starts the digestive process. You get more saliva and start producing more enzymes and acids for a meal your body thinks is soon to come. All this from just smell. If you don’t eat, then you can fill with gas since the enzymes, etc. don’t have food to work on. They lay in your gut, irritate it, and you get gas.
Years ago my stomach would look 4 months pregnant from gas after most meals, and it sure did hurt. I didn’t figure out until years later that I had Candida and gluten issues. It happened again a few days back after eating too many potato chips. I cheated, so I paid for it with gas. It took hours for the gas to move out. I can’t eat more then 20-25 grams of carbohydrates a day. That would roughly translate into 4 or 5 servings of vegetables a day (1/4 to 1/2 cup per serving). Anything over that and I get too much gas.
I had a friend who suffers from a muscle jerking disease Myoclonus, who looked 9 months pregnant all the time. Very rarely did her stomach go down, and when it did, I’d ask her what she didn’t eat. She had no clue. She once went on a diet that happened to eliminate grains and dairy. She lost weight, and her belly flattened. She didn’t stay with it long, so she swelled up again. Her mother must be gluten intolerant since she has Parkinson’s, diabetes, and heart issues linked to gluten. Her brother is celiac from childhood, never gave gluten up, and now has Lymphoma. I’m sure my friend is gluten intolerant, but she won’t give it up.