Differential Diagnosis

The patient presents with a history of colitis and recent onset of diarrhea that has changed to a yellowish color. Here's a differential diagnosis organized into categories:

• Single most likely diagnosis
  • Relapse of Inflammatory Bowel Disease (IBD): Given the patient's history of colitis, a relapse of IBD is the most likely diagnosis. The change in stool color to yellowish could indicate an increase in inflammation and potentially the presence of blood or pus in the stool.
• Other Likely diagnoses
  • Infectious Colitis: The patient's symptoms could be due to an infectious cause, such as a bacterial or viral infection, which is common in patients with a history of colitis.
  • Irritable Bowel Syndrome (IBS): Although less likely, IBS could be a consideration, especially if the patient's symptoms are not as severe as those typically seen in IBD.
• Do Not Miss
  • Clostridioides difficile (C. diff) Infection: This is a potentially life-threatening condition that can cause severe diarrhea and colitis, especially in patients with a history of antibiotic use or recent hospitalization.
  • Toxic Megacolon: A rare but potentially deadly complication of colitis, characterized by a very inflated colon that can rupture and lead to peritonitis.
• Rare diagnoses
  • Microscopic Colitis: A type of colitis that is characterized by inflammation of the colon lining, but is less common than IBD or infectious colitis.
  • Lymphocytic Colitis: A rare condition characterized by inflammation of the colon lining, which can cause chronic diarrhea and abdominal pain.
  • Eosinophilic Colitis: A rare condition characterized by an accumulation of eosinophils in the colon lining, which can cause inflammation and diarrhea.