My husband works on an assembly line, and today, he came home complaining of abdominal pain. It started on the right side of his stomach, and he said that whenever he moved a certain way, he felt a sharp pain about 5 inches below his heart. Now, I felt his stomach, where he says it hurts, and there is a huge knot right above his belly button. I do not know if it's hard or tender, because as soon as I touched it, he winced and jumped back from me. I want to take him to the ER, but he's fighting me on this. What can it be?