Duodenal Ulcer: Pain from duodenal ulcers typically increases with food intake because eating stimulates the release of gastric acid, which can exacerbate the ulceration in the duodenum.

Gastritis: Inflammation of the stomach lining can cause pain that worsens with eating, especially if the food is spicy, fatty, or acidic.
Stomach Ulcer (Gastric Ulcer): Although less common than duodenal ulcers, gastric ulcers can also cause pain related to food intake. However, the pain pattern may differ, sometimes improving with eating.
Functional Dyspepsia: A condition characterized by recurring signs and symptoms of indigestion that have no obvious cause. Symptoms can include pain or discomfort in the upper abdomen that may worsen with eating.

Gastroesophageal Reflux Disease (GERD): While GERD typically presents with heartburn and regurgitation, some patients may experience chest pain or abdominal discomfort that worsens with eating, particularly with large or fatty meals.
Pancreatitis: Acute or chronic inflammation of the pancreas can cause severe abdominal pain that radiates to the back and may worsen after eating, especially fatty foods.
Cholecystitis: Inflammation of the gallbladder, often due to gallstones, can cause right upper quadrant abdominal pain that worsens with fatty food intake.

Zollinger-Ellison Syndrome: A rare disorder characterized by excessive gastric acid production due to a gastrin-producing tumor, leading to severe ulcers and diarrhea.
Carcinoma of the Stomach or Duodenum: Although rare, cancer in the stomach or duodenum can present with symptoms similar to ulcers, including pain that worsens with eating.
Eosinophilic Gastroenteritis: A rare condition characterized by eosinophilic infiltration of the gastrointestinal tract, which can cause abdominal pain, nausea, and vomiting, potentially worsening with food intake.