Why Does My Palms & The Bottom Of My Feet Itch?

I've had a couple of digestive tract disturbances. The first time in October I thought I had food poisoning from something I'd eaten. I experienced abdomenal pain, nausea, vomiting and an upset stomach. The most recent took place last week. I had abdomenal, right shoulder and lower back pain but none of the other symptoms. This time the palms of my hands and bottom of my feet itch.