Differential Diagnosis for 18 YO Male with Low Abdo Pain, Frequent BMs, and Other Symptoms

• Single Most Likely Diagnosis
  • Inflammatory Bowel Disease (IBD), specifically Ulcerative Colitis (UC): The symptoms of low abdominal pain, frequent bowel movements, jelly-like stools (possibly indicating mucous), and occasional trace blood are classic for UC. The elevated CRP (54.2) supports an inflammatory process, which is consistent with IBD. The absence of WBC elevation does not rule out UC, as it can be normal in some cases, especially if the patient is not having an acute flare.
• Other Likely Diagnoses
  • Crohn's Disease: Another form of IBD that can present with similar symptoms, though it more commonly affects the small intestine and can have a wider range of symptoms, including weight loss and fever. The absence of significant WBC elevation and specific mention of "jelly stools" slightly lessens its likelihood compared to UC but still keeps it in the differential.
  • Infectious Colitis: Could be caused by bacterial, viral, or parasitic infections. Symptoms can overlap with IBD, including abdominal pain, frequent stools, and blood. However, the chronic nature suggested by the symptoms and the lack of WBC elevation make this less likely.
• Do Not Miss Diagnoses
  • Intussusception: A condition where a part of the intestine telescopes into another, which can cause abdominal pain, bloody stools, and is a surgical emergency. Though less common in adults, it's crucial not to miss due to its potential for severe complications.
  • Appendicitis: Typically presents with right lower quadrant pain, but atypical presentations can occur, especially in younger patients. The absence of WBC elevation and the nature of the pain do not strongly support this diagnosis, but its potential severity warrants consideration.
  • Ischemic Colitis: More common in older adults but can occur in younger individuals, especially with risk factors like hypercoagulability or vasculitis. It presents with sudden onset of abdominal pain and bloody diarrhea.
• Rare Diagnoses
  • Ehlers-Danlos Syndrome with Gastrointestinal Involvement: A genetic disorder that can lead to bowel perforation, obstruction, or gastrointestinal bleeding, among other symptoms. The combination of abdominal pain, altered bowel habits, and possible bleeding could, in rare cases, be related to this syndrome.
  • Behçet's Disease: A form of vasculitis that can affect the gastrointestinal tract, presenting with symptoms like abdominal pain, diarrhea, and bleeding. It's rare and typically associated with other systemic symptoms like oral and genital ulcers.