Differential Diagnosis

The patient's symptoms of slow weight loss, constant epigastric pain, and occasional loose stools, along with positive fecal calprotectin and transferrin rapid test arrays, suggest an underlying gastrointestinal issue. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Inflammatory Bowel Disease (IBD), specifically Crohn's disease: The patient's symptoms of weight loss, abdominal pain, and loose stools, combined with positive fecal calprotectin (indicating intestinal inflammation) and a history of Mallory-Weiss tears, suggest IBD. The lack of improvement on a bland diet and omeprazole further supports this diagnosis, as IBD often requires specific treatment beyond symptom management.

• Other Likely Diagnoses

  • Irritable Bowel Syndrome (IBS): Although the patient has some symptoms consistent with IBS, such as abdominal pain and altered bowel habits, the presence of weight loss, positive inflammatory markers, and lack of response to dietary changes make IBS less likely.
  • Gastroparesis: Given the patient's history of gallbladder removal and symptoms worsening with stress and activity, gastroparesis could be considered, especially with the finding of retention in the piriform sinus on barium swallow. However, the presence of inflammatory markers and loose stools points more towards an inflammatory process.
  • Peptic Ulcer Disease: Despite the patient being H. pylori negative, peptic ulcer disease could still be a consideration, especially with a history of epigastric pain and Mallory-Weiss tears. However, the lack of response to omeprazole and the presence of inflammatory markers in the stool make this less likely.

• Do Not Miss Diagnoses

  • Gastric Cancer: Although less likely given the patient's age, gastric cancer must be considered, especially with symptoms of weight loss, abdominal pain, and a history of H. pylori negativity but with other risk factors such as a history of gastric pathology (Mallory-Weiss tears).
  • Intestinal Lymphoma: This is a rare condition but must be considered in the differential diagnosis of chronic gastrointestinal symptoms, especially with weight loss and lack of response to standard treatments.

• Rare Diagnoses

  • Eosinophilic Gastroenteritis: This condition involves eosinophilic infiltration of the gastrointestinal tract and can present with abdominal pain, weight loss, and gastrointestinal symptoms. It's a rare condition and would require specific diagnostic testing for confirmation.
  • Chronic Intestinal Pseudo-obstruction: This is a rare condition characterized by recurrent episodes of intestinal obstruction without any mechanical obstruction. It could explain some of the patient's symptoms, such as abdominal pain and altered bowel habits, but is less likely given the inflammatory markers and other findings.