Hello, Welcome to Just Answer and thanks for your question. A phlebolith is a calcification within the wall of a vein. It is seen by a vascular specialist if it is symptomatic. Generally they are harmless and cause no symptoms. They can be a symptom of having another disease though such as a hemangioma (a benign tumor) in the colorectal area. They are sometimes difficult to differentiate from kidney stones depending on where they are.