Differential Diagnosis for 18-year-old Female with Persistent Nausea, Vomiting, and Diarrhea
- Single most likely diagnosis:
- Gastroenteritis: This is the most likely diagnosis given the patient's symptoms of nausea, vomiting, and diarrhea for 2 weeks. The lack of correlation with food intake, absence of abdominal pain, and negative pregnancy tests support this diagnosis. Gastroenteritis can be caused by viral or bacterial infections, and the patient's symptoms are consistent with a viral etiology.
- Other Likely diagnoses:
- Irritable Bowel Syndrome (IBS): The patient's symptoms of persistent nausea, vomiting, and diarrhea could be consistent with IBS, especially given the absence of abdominal pain and other alarming symptoms. However, the acute onset of symptoms makes this diagnosis less likely.
- Inflammatory Bowel Disease (IBD): Although less likely, IBD (e.g., Crohn's disease or ulcerative colitis) could present with similar symptoms. The patient's age and lack of other symptoms (e.g., weight loss, abdominal pain) make this diagnosis less likely.
- Food intolerance or sensitivity: The patient's symptoms could be related to a food intolerance or sensitivity, although she denies any changes in her diet.
- Do Not Miss diagnoses:
- Pregnancy-related complications: Although the patient has had negative pregnancy tests, it is essential to consider pregnancy-related complications, such as ectopic pregnancy or miscarriage, especially given her IUD use.
- Appendicitis: Although the patient denies abdominal pain, appendicitis can present with nausea, vomiting, and diarrhea. It is crucial to consider this diagnosis to avoid missing a potentially life-threatening condition.
- Inflammatory or infectious causes (e.g., diverticulitis, intestinal obstruction): These conditions can present with similar symptoms and require prompt medical attention to avoid complications.
- Rare diagnoses:
- Celiac disease: This autoimmune disorder can cause gastrointestinal symptoms, including nausea, vomiting, and diarrhea, although it is less common in this age group.
- Giardiasis: This parasitic infection can cause similar symptoms, although it is less common in the United States and typically associated with travel or exposure to contaminated water.
- Other rare infectious causes (e.g., norovirus, rotavirus): These viruses can cause severe gastrointestinal symptoms, although they are less common in this age group and typically associated with specific risk factors (e.g., travel, exposure to contaminated food or water).