Just had a chip butty within 15 minutes stomach cramps and been sick what up

Do I have irritable bowel or GI

Or E.coli or salmonella or something else. Better to see your doctor.

There may have been something about the grease the chips were fried in -- maybe rancid or was past its prime. Did you take anything for relief of digestion problems?

I would go and see a doctor

It doesn't sound like irritable bowel syndrome as that generally causes diarrhoea or constipation due to the bowel working to slow or to fast at times.

It could be food poisoning due to that generally comes on stright away if the food was really bad.