Differential Diagnosis

The patient presents with longstanding gastrointestinal issues, including daily nausea, abdominal discomfort, and a history of gastritis. The following differential diagnosis is organized into categories:

• Single most likely diagnosis
  • Irritable Bowel Syndrome (IBS): The patient's symptoms of chronic abdominal discomfort, nausea, and bowel habits without evidence of inflammation or structural abnormalities are consistent with IBS. The patient's history of trying various medications and dietary changes without significant relief also supports this diagnosis.
• Other Likely diagnoses
  • Functional Dyspepsia: The patient's symptoms of upper abdominal discomfort, nausea, and bloating are consistent with functional dyspepsia. The patient's history of gastritis and negative diagnostic tests for other conditions also support this diagnosis.
  • Eosinophilic Gastroenteritis: The patient's elevated IgE level and history of food allergies may suggest an allergic or eosinophilic component to their gastrointestinal symptoms.
  • Gastroparesis: The patient's symptoms of nausea, vomiting, and abdominal discomfort could be consistent with gastroparesis, particularly given their history of gastritis and use of medications that can slow gastric emptying.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Inflammatory Bowel Disease (IBD): Although the patient's diagnostic tests have been negative, IBD (e.g., Crohn's disease, ulcerative colitis) can present with non-specific symptoms and requires careful consideration to avoid missing the diagnosis.
  • Gastric Cancer: The patient's history of gastritis and abdominal symptoms warrants consideration of gastric cancer, particularly given their age and duration of symptoms.
  • Small Intestine Bacterial Overgrowth (SIBO): The patient's symptoms of bloating, abdominal discomfort, and diarrhea could be consistent with SIBO, which can be a complication of gastroparesis or other conditions.
• Rare diagnoses
  • Mast Cell Activation Syndrome: The patient's elevated IgE level and history of food allergies may suggest a mast cell disorder, which can present with gastrointestinal and other systemic symptoms.
  • Celiac Disease (despite negative tests): Although the patient's celiac disease tests have been negative, it is possible that they have a rare or atypical form of the disease, or that the tests were false negatives.
  • Chronic Intestinal Pseudo-Obstruction: The patient's symptoms of abdominal discomfort, nausea, and bloating could be consistent with chronic intestinal pseudo-obstruction, a rare condition characterized by impaired intestinal motility.