Differential Diagnosis

Given the patient's normal abdominopelvic CT scan findings with oral and IV contrast and no evidence of leaks, the differential diagnosis can be organized into the following categories:

• Single Most Likely Diagnosis
  • Functional gastrointestinal disorder (e.g., irritable bowel syndrome): This is a common condition that could present with abdominal symptoms not explained by other findings on the CT scan.
• Other Likely Diagnoses
  • Inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis) in early stages or in remission: These conditions might not always show clear abnormalities on a CT scan, especially if the disease is mild or in a quiescent phase.
  • Gastroenteritis: Viral or bacterial infections could cause symptoms without significant findings on a CT scan.
  • Adhesions or early small bowel obstruction not yet causing significant dilatation: These conditions might not be evident on a CT scan if they are not causing significant obstruction or if the obstruction is intermittent.
• Do Not Miss Diagnoses
  • Early appendicitis: Although the CT scan is sensitive for appendicitis, very early cases might not show the typical signs of appendiceal enlargement or wall thickening.
  • Mesenteric ischemia: This condition can be subtle on imaging, especially in its early stages, and requires a high index of suspicion.
  • Ovarian torsion: While more commonly diagnosed in women, ovarian torsion can occur without specific findings on CT, especially if the torsion is intermittent.
• Rare Diagnoses
  • Intussusception in adults: This condition is more common in children but can occur in adults, often with a lead point such as a tumor, and might not always be evident on CT.
  • Eosinophilic gastroenteritis: A rare condition characterized by eosinophilic infiltration of the gastrointestinal tract, which might not have specific findings on CT scan.
  • Chronic intestinal pseudo-obstruction: A rare disorder characterized by recurrent episodes of small bowel obstruction without any mechanical obstruction, which could have non-specific or normal findings on CT scan.

Each of these diagnoses is considered based on the lack of specific findings on the CT scan and the need to consider a broad range of possibilities when evaluating abdominal symptoms. The justification for each includes the potential for the condition to present with non-specific symptoms and either normal or non-diagnostic imaging findings.