I have blood in my stool, I take 125mg of Synthroid, I have no discomfort or pain, could the Synthroid be the cause?

It is possible that blood in the stool could be caused by hemorrhoids or an external anal fissure without constipation. If the blood was bright red and has decreased significantly, it may be less concerning. However, it is important to monitor closely and consult a doctor if the bleeding reappears. The doctor can conduct further investigations to diagnose the cause of the bleeding. It may also be necessary to continue monitoring your TSH levels, although this is not directly related to the bleeding.