Q: What are the risks involved in a colonoscopy for a person who has suffered portal vein thrombosis and is on Coumadin and has developed anaemia and probably has verisis. The cause of anaemia is not known. This person also has an enlarged spleen. What could be the cause of anaemia? Would virtual colonoscopy be a preferred testing method?

A:There is no extra risk for colonoscopy in patients who have portal vein thrombosis and are on anticoagulation except for the usual risks of colonoscopy which is 1. Sedation related 2. Small risk of perforation: maybe less than 1 in 10 000 However in patients who have portal vein thrombosis and are on blood thinning products, there is a risk of bleeding if a procedure such as biopsy or snaring is done. A simple diagnostic colonoscopy without biopsy is very safe. Without access to a detailed medical report, the causes of anaemia in this situation are a) Portal vein thrombosis and hypersplenism which results in breakdown of red blood cells in the spleen. b)Loss of small amount of blood from the intestine as a result of congestion of blood in the intestine because of portal vein thrombosis or because of anticoagulation therapy. c) Finally if the cause of portal vein thrombosis is myelodysplastic syndrome, then again there can be anaemia. Colonoscopy would be better as compared to virtual CT colonoscopy as if there is a different cause for bleeding it can be dealt with after checking the prothrombin time and the platelet count.