Fat-laden fried food might cause stomachaches and diarrhea. Fried food also causes acid reflux.
Citrus relaxes the esophageal sphincter, letting acid in and causing heartburn. Acid can prevent stomach emptying, causing heartburn.
Some people get heartburn from peppermint. Peppermint relaxes the stomach-esophageal sphincter.
Oligosaccharides, fermentable fibers in beans, can induce gas, bloating, and abdominal pain. Because they bypass the stomach and enter the colon, they're good for the gut.
Cabbage, broccoli, kale, and collard greens are cruciferous vegetables. They include sugars like beans that cause gas, bloating, and abdominal pain.
Spicy food relaxes the sphincter (or valve) between the stomach and esophagus, allowing acidic food to reflux into the esophagus and cause heartburn.
Sugar alcohol-based candies, gum, and other sugar-free products might cause stomachaches and flatulence. Sorbitol, mannitol, xylitol, erythritol, and malititol are "-ol" sweeteners.
Like peppermint and citrus fruit, chocolate relaxes the esophageal sphincter, causing heartburn and indigestion. It depends on the person.