Differential Diagnosis

• Single most likely diagnosis
  • Gastroenteritis: This is a common condition that can cause nausea, vomiting, and sometimes diarrhea, although the patient denies diarrhea. The lack of abdominal pain and fever does not rule out gastroenteritis, as these symptoms can vary. The failure of zofran to provide relief does not significantly impact this likelihood since zofran is often used for symptom management rather than treating the underlying cause.
• Other Likely diagnoses
  • Food Poisoning: Similar to gastroenteritis, food poisoning can cause nausea and vomiting without abdominal pain or fever. The onset and the fact that symptoms have persisted for over a week could suggest a more prolonged gastrointestinal issue.
  • Viral Gastroenteritis (Norovirus): This is highly contagious and can cause severe vomiting, which fits the patient's symptoms. The absence of fever and abdominal pain does not rule out norovirus infection.
  • Medication-induced Nausea and Vomiting: Although the patient mentions trying zofran, the question does not specify current medications that could be causing these symptoms. Some medications can induce nausea and vomiting as side effects.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Appendicitis: Although the patient denies abdominal pain, which is a hallmark symptom, some cases of appendicitis can present atypically, especially in the early stages or in certain populations like the elderly or young children. Vomiting can occur before pain becomes a dominant symptom.
  • Intestinal Obstruction: This is a surgical emergency that can present with vomiting. Early on, abdominal pain might not be prominent, and the absence of diarrhea or fever does not rule out this condition.
  • Pregnancy-related Morning Sickness: In women of childbearing age, morning sickness can be severe and persistent, leading to frequent vomiting. This diagnosis would be critical to consider due to the implications for pregnancy care.
• Rare diagnoses
  • Cyclic Vomiting Syndrome: A rare condition characterized by recurrent episodes of severe vomiting lasting hours to days, with periods of normal health in between. The absence of abdominal pain and the specific pattern of vomiting could suggest this diagnosis.
  • Gastroparesis: A condition where the stomach takes too long to empty its contents, which can cause nausea, vomiting, and feeling full after eating only a small amount of food. It might not always present with abdominal pain or fever.