Differential Diagnosis for Outpouching of Sigmoid Colon

Single Most Likely Diagnosis

• Diverticulum: The most common cause of an outpouching of the sigmoid colon, diverticula are small, bulging pouches that can form in the wall of the colon. They are often asymptomatic but can cause symptoms if they become inflamed or bleed.

Other Likely Diagnoses

• Polyp: A growth on the inner lining of the colon, polyps can sometimes appear as outpouchings. They are usually benign but can have the potential to become cancerous over time.
• Colonic Lipoma: A rare, benign tumor composed of fat tissue, colonic lipomas can cause outpouching of the colon wall.
• Inflammatory Pseudopolyp: Seen in conditions like inflammatory bowel disease (IBD), these are areas of regenerating mucosa that can appear as outpouchings.

Do Not Miss Diagnoses

• Colorectal Cancer: Although less likely, an outpouching could be a sign of colorectal cancer, especially if it's a new finding or associated with other symptoms like weight loss or changes in bowel habits. Missing this diagnosis could be fatal.
• Infectious Colitis: Certain infections can cause outpouching-like appearances due to inflammation and ulceration of the colon wall. Missing an infectious cause could lead to severe complications if not treated promptly.

Rare Diagnoses

• Colonic Duplication: A rare congenital anomaly where there is a duplication of a portion of the colon, which can appear as an outpouching.
• Gastrointestinal Stromal Tumor (GIST): A rare type of tumor that occurs in the digestive tract, GISTs can sometimes cause outpouching of the colon wall.
• Amyloidosis: A condition characterized by the deposition of amyloid proteins in various tissues, including the colon, which can lead to outpouching-like appearances due to wall thickening and rigidity.