Differential Diagnosis for a 19-year-old Male with Diarrhea and Abdominal Pain
Single Most Likely Diagnosis
- Viral Gastroenteritis: This is the most common cause of acute diarrhea and abdominal pain in young adults, often caused by norovirus or rotavirus, and typically resolves on its own within a few days to a week.
Other Likely Diagnoses
- Bacterial Gastroenteritis: Caused by bacteria such as E. coli, Salmonella, or Campylobacter, which can be acquired through contaminated food or water. Symptoms can be similar to viral gastroenteritis but may be more severe.
- Food Poisoning: Similar to bacterial gastroenteritis but typically has a shorter incubation period and is often related to the consumption of specific foods.
- Irritable Bowel Syndrome (IBS): A chronic condition characterized by recurring abdominal pain and changes in bowel movements, which could be exacerbated by stress, diet, or other factors.
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis, which are chronic and can cause diarrhea, abdominal pain, and other symptoms, though they typically have a more gradual onset.
Do Not Miss Diagnoses
- Appendicitis: Although the patient does not have fever, appendicitis can present with abdominal pain and diarrhea, especially if the appendix is located near the rectum. Missing this diagnosis could lead to severe consequences, including perforation and peritonitis.
- Intussusception: A condition where a part of the intestine slides into another, which can cause bowel obstruction and ischemia. It's rare in adults but can be life-threatening if not promptly treated.
- Mesenteric Ischemia: A condition caused by reduced blood flow to the intestines, which can lead to ischemia and necrosis of the bowel tissue. It's more common in older adults but can occur in younger individuals with risk factors such as hypercoagulable states.
Rare Diagnoses
- Giardiasis: An intestinal infection caused by the Giardia parasite, which can lead to chronic diarrhea and abdominal pain. It's more common in individuals who have traveled to areas with poor sanitation or have been exposed to contaminated water.
- Whipple's Disease: A rare, systemic bacterial infection that can cause diarrhea, abdominal pain, and malabsorption, among other symptoms.
- Celiac Disease: An autoimmune disorder that causes the immune system to react to gluten, leading to inflammation and damage in the small intestine, which can cause chronic diarrhea and abdominal pain.