Stomach pain

We'd not been flying for long on our way to Spain for a short break, when the wife began having stomach pain. She called the stewardess over and informed her.

"It's possibly something you've eaten." Said the stewardess, sympathetically. "Have a little think, see if you can remember for me what you've had today, lovey."

"Well not much today, what with rushing around to get checked-in for noon." Explained the wife. "So it was just the four sausage, two egg, bacon and black pudding for breakfast, with mushrooms, tinned tomatoes, just a few beans, I've gone right off them, and a couple of slices of fried bread. Then at a toilet stop at motorway services I grabbed a couple of mars bars... well that's what I wanted, but they didn't have any so I had to get a three-foot novelty Toblerone instead. And a large bag of Doritos. We made good time the rest of the way and got to the airport ten minutes early, so I popped into Burger King and had a whopper and milkshake. Don't like the chips though. Onion rings for me any day."

"I think I've got just the remedy." Said the stewardess. "Get your tummy feeling better."

"Oh, thank you." Said the wife. "Is it as a liquid medicine, or a tablet?"

"Neither.

Spoiler:

It's a bl**dy seatbelt extender, you greedy fat "