What medical condition results from irritation and swelling of the pancreas?

Pancreatitis is the correct answer as it specifically refers to the inflammation of the pancreas, which can result from various factors including excessive alcohol consumption, certain medications, and gallstones. When the pancreas becomes irritated and swollen, it can lead to severe abdominal pain, digestive issues, and even systemic complications.

Understanding the specifics of pancreatitis is crucial, as it not only affects the pancreas but can also disrupt the digestive process and impact overall health. Contrastingly, the other conditions mentioned do not involve the pancreas. Cholecystitis relates to inflammation of the gallbladder, painful gallbladder syndrome is more about gallbladder-related pain rather than inflammation, and gastritis pertains to the inflammation of the stomach lining. Each of these conditions affects different organs and systems in the body, underscoring why pancreatitis is uniquely identified as the swelling and irritation of the pancreas.