When adrenaline rushes through your body, your blood goes to the places that your body feels need it most. That means that your blood is rushing to your heart, your brain, and possibly various muscles, and to do that it rushes out of your legs and makes them feel more like jelly.
Since acid is a primary cause of ulcers, you want to completely avoid any foods with high acidic content. Among them: alcohol, black and red peppers, chili powder and hot peppers, all of which irritate the stomach lining, and coffee, tea, colas, or chocolate, which can increase the amount of stomach acid.
Each individual has different types of foods that trigger diarrhea, and for many the offending source is spicy foods. The chemicals in spicy foods may irritate your stomach or cause indigestion. Spicy foods can also trigger acid reflux. The active ingredient in hot peppers -- capsaicin -- may increase digestive fluids in your stomach. However, capsaicin may actually help relieve diarrhea by fighting bacteria that can cause loose stools, according to Wake Forest Baptist Health.