Differential Diagnosis for 18-year-old Female with Nausea, Vomiting, and Gastrointestinal Bleeding
Single Most Likely Diagnosis
- Gastroenteritis: This is the most likely diagnosis given the acute onset of nausea, vomiting, diarrhea, and the presence of red blood in the stool. The positive fecal occult blood test and the presence of red blood cells in the urine also support this diagnosis. The patient's symptoms and laboratory results, such as elevated white blood cell count and lactic acid, are consistent with an infectious or inflammatory process.
Other Likely Diagnoses
- Inflammatory Bowel Disease (IBD): The presence of red blood in the stool, diarrhea, and abdominal pain could suggest the onset of IBD, such as Crohn's disease or ulcerative colitis. However, the acute onset and the absence of a significant history of similar symptoms make this less likely than gastroenteritis.
- Food Poisoning: This could be a possible diagnosis given the acute onset of symptoms, especially if the patient recently consumed contaminated or spoiled food. The presence of diarrhea, vomiting, and abdominal pain supports this diagnosis.
- Intestinal Infection: An infection caused by bacteria, viruses, or parasites could explain the patient's symptoms. The presence of red blood in the stool and diarrhea suggests an invasive intestinal infection.
Do Not Miss Diagnoses
- Intussusception: Although rare in adults, intussusception can cause intestinal obstruction and bleeding, presenting with abdominal pain, vomiting, and bloody stools. It is a medical emergency that requires prompt diagnosis and treatment.
- Mesenteric Ischemia: This condition involves insufficient blood flow to the intestines and can cause abdominal pain, vomiting, and bloody stools. It is a life-threatening condition that requires immediate medical attention.
- Appendicitis: Although the patient's symptoms do not typically suggest appendicitis, it is a condition that should not be missed due to its potential for serious complications if left untreated.
Rare Diagnoses
- Hemolytic Uremic Syndrome (HUS): This is a rare condition characterized by hemolytic anemia, acute kidney injury, and thrombocytopenia. Although the patient's laboratory results do not strongly suggest HUS, it is a rare diagnosis that should be considered in the differential diagnosis of gastrointestinal bleeding and renal involvement.
- Ehlers-Danlos Syndrome: This is a rare genetic disorder that can cause gastrointestinal bleeding and other systemic symptoms. However, the patient's presentation does not strongly suggest this diagnosis, and it would be considered only if other more likely diagnoses are ruled out.