[Shasown]

If you are passing blood anally, it could be due to a number of relatively harmless problems, if its fresh blood it could be an anal fissure(a tear in the ringpiece) or haemorrhoids (piles). If blood is being passed into the digestive system further up the colon it interracts with digestive juices and comes out like coffee grounds. Either way its best to get any bleeding in that area investigated fully.

Next time you do go to the doctor have a chat about IBS and also enquire if the symptoms you are suffering from, could be psychosomatic in origin, basically is the worry about becoming ill, or over worrying over harmless symptoms manifesting or increasing these symptoms. Sometimes panic and worry can cause the mind to create problems.