Differential Diagnosis for Chronic Recurrent Severe Left Upper Quadrant (LUQ) Pain

Single Most Likely Diagnosis

• Functional Dyspepsia: Given the chronic mild gastritis, normal lab markers, and absence of H. pylori, functional dyspepsia is a plausible diagnosis. The presence of duodenum foveolar metaplasia could be incidental, and the normal MRCP and elastase levels suggest that pancreatic and biliary diseases are less likely.

Other Likely Diagnoses

• Gastroesophageal Reflux Disease (GERD): Although not directly indicated by the provided information, GERD can cause chronic recurrent severe LUQ pain and should be considered, especially if symptoms worsen with food intake or lying down.
• Chronic Pancreatitis: Despite the normal MRCP and elastase levels, early or mild chronic pancreatitis might not always be detected by these tests. The presence of duodenum foveolar metaplasia could be related to chronic pancreatic inflammation.
• Irritable Bowel Syndrome (IBS): While IBS typically presents with abdominal pain that is more diffuse or lower, some patients can experience upper abdominal pain, making it a consideration in the differential diagnosis.

Do Not Miss Diagnoses

• Peptic Ulcer Disease: Although H. pylori is negative, peptic ulcers can still occur due to NSAID use or other causes. The presence of chronic gastritis and duodenum foveolar metaplasia keeps this in the differential.
• Pancreatic Cancer: Although rare and less likely given the normal imaging and lab tests, pancreatic cancer can present with nonspecific abdominal pain and should not be missed due to its severe prognosis.
• Gastric Cancer: Similarly, gastric cancer, though less common, can present with chronic abdominal pain and should be considered, especially if there are risk factors or if the patient's symptoms change.

Rare Diagnoses

• Eosinophilic Gastroenteritis: A rare condition characterized by eosinophilic infiltration of the gastrointestinal tract, which can cause chronic abdominal pain, nausea, and vomiting.
• Celiac Disease: An autoimmune reaction to gluten, leading to small intestine inflammation, which can sometimes present with upper abdominal pain.
• Sphincter of Oddi Dysfunction: A rare condition that affects the sphincter of Oddi, leading to recurrent episodes of abdominal pain, typically in the upper abdomen, which can mimic other conditions like pancreatitis or cholecystitis.