An ostomy is a surgical opening created in the abdomen if an intestinal segment is damaged due to disease or injury and cannot be repaired. Body waste is eliminated through the ostomy. Ostomies that expel feces are called colostomies or ilestomies.

When the ostomy is created waste is expelled through a stoma, or the ending of the large intestine that protrudes out of the abdominal wall. The stoma is oval-shaped and can vary in size depending on the procedure and abdominal shape.