What would cause stomach pain after eating leafy greens? had this ever since i was little but getting worse now?

Stomach Pain: Abdominal pain after eating is not normal, and may result from any of a very large list of possible causes. To understand your pain better, and to arrive at a diagnosis, you should see a doctor, who will ask you a series of specific questions aimed at better defining the pain. Some common causes of abdominal pain after eating include peptic ulcer disease, gallstones and mesenteric ischemia.