The main causes of colitis are:
• Infections: Bacterial, viral, or parasitic infections.
• Inflammatory bowel disease (IBD): Includes UC and Crohn's disease.
• Ischemia: Reduced blood flow to the colon.
• Medications: Certain drugs such as NSAIDs and antibiotics.
• Microscopic colitis: Includes collagenous colitis and lymphocytic colitis.