Differential Diagnosis

The patient's symptoms of nausea, vomiting, and abdominal discomfort, particularly triggered by oily foods and occurring at night, suggest a range of possible diagnoses. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Functional Dyspepsia: This condition is characterized by recurring symptoms of upper abdominal discomfort or pain, early satiety, and difficulty swallowing, not necessarily related to bowel movements. The patient's symptoms of feeling full, nausea, and vomiting, especially after consuming oily foods, align with functional dyspepsia. The absence of alarm symptoms such as significant weight loss, bleeding, or severe pain also supports this diagnosis.

• Other Likely Diagnoses

  • Gastroesophageal Reflux Disease (GERD): Symptoms like nausea, vomiting, and abdominal soreness, particularly at night, could be indicative of GERD, especially if the patient experiences relief when sitting up or worsening when lying down.
  • Irritable Bowel Syndrome (IBS): Although the patient mentions no significant changes in bowel movements, IBS can sometimes present with nausea and vomiting, especially if the patient has a subtype that involves upper gastrointestinal symptoms.
  • Food Intolerance: Given the patient's reaction to oily foods, an intolerance to certain types of food could be a contributing factor, leading to symptoms of nausea and vomiting.

• Do Not Miss Diagnoses

  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can present with nausea, vomiting, and abdominal pain. Although less likely given the absence of bloody stools, weight loss, and significant abdominal pain, IBD is a critical diagnosis not to miss due to its potential for serious complications.
  • Gastric Ulcer or Duodenal Ulcer: These conditions can cause similar symptoms, including nausea and vomiting, especially if related to food intake. The absence of severe abdominal pain does not rule out ulcers, as some patients may have minimal pain.
  • Appendicitis: Although the patient's symptoms do not strongly suggest appendicitis (given the lack of severe abdominal pain, fever, and specific localization of pain), it's a diagnosis that must be considered due to its potential for severe consequences if missed.

• Rare Diagnoses

  • Cyclic Vomiting Syndrome: Characterized by recurrent, severe episodes of vomiting, this condition can be associated with abdominal pain and nausea. It's less common and might be considered if other diagnoses are ruled out.
  • Gastroparesis: A condition where the stomach takes too long to empty its contents, which can lead to nausea, vomiting, and feeling full after eating. It's less likely without other symptoms like significant bloating or weight loss but remains a possibility.
  • Eosinophilic Esophagitis or Gastroenteritis: These conditions involve an immune response to food or environmental allergens, leading to inflammation and symptoms that could include nausea and vomiting. They are less common and typically associated with other symptoms like difficulty swallowing or significant abdominal pain.