Differential Diagnosis for Transverse Colon Abnormality

The given clinical presentation involves the transverse colon with hyperaemic mucosa, multiple ulcers, and a normal rest of the colon and rectum. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Ischaemic Colitis: This condition is characterized by inflammation of the colon due to decreased blood flow, which can lead to hyperaemic mucosa and ulcerations. The fact that the rest of the colon and rectum are normal suggests a localized process, which is consistent with ischemic colitis, especially if the patient has risk factors such as vascular disease or low blood pressure.

• Other Likely Diagnoses

  • Crohn’s Disease: Although Crohn's disease can affect any part of the gastrointestinal tract and often spares the rectum, it typically involves the terminal ileum. However, it can present with skip lesions, where areas of disease are separated by normal-appearing bowel. The presence of multiple ulcers in the transverse colon could be consistent with Crohn's disease, especially if there are other supportive findings like cobblestoning or a history suggestive of chronic disease.
  • Pseudomembranous Colitis: This condition, often caused by Clostridioides difficile infection, can present with colonic inflammation, ulcers, and pseudomembranes. While it typically involves more of the colon, localized disease can occur, especially in the context of antibiotic use or healthcare exposure.

• Do Not Miss Diagnoses

  • Infectious Colitis: Certain infections (e.g., Salmonella, Shigella, Campylobacter) can cause localized colonic inflammation and ulceration. Missing these diagnoses could lead to inappropriate treatment and potential complications.
  • Neutropenic Colitis (Typhlitis): This condition occurs in neutropenic patients and can present with localized colonic inflammation and ulceration, often in the cecum but potentially in other areas like the transverse colon. It's a medical emergency requiring prompt recognition and treatment.

• Rare Diagnoses

  • Behçet’s Disease: A rare condition characterized by systemic vasculitis that can involve the gastrointestinal tract, leading to ulcers and inflammation. Colonic involvement is less common than oral or genital ulcers but can occur.
  • Eosinophilic Colitis: A condition characterized by eosinophilic infiltration of the colonic wall, which can cause inflammation, ulcers, and other symptoms. It's a rare diagnosis that might be considered if other more common causes are ruled out.