Hello, I went through your query, some of the hypothyroid patients presents with throat pain, if you have regular follow up with your doctor regarding thyroid status, and dose adjusted properly nothing to worry. If you have throat pain with symptoms of common cold, then it is sore throat, do salt water (warm) gargling, drink some hot coffee or tea. Most common cause for black coloured stools is iron tablets or syrups, nothing to worry about it, continue your tablets. Other cause is Bleeding in the upper digestive tract (oesophagus, stomach) tends to cause black, tarry stools as the blood is digested for longer than bleeding from the colon, rectum or around the anus which tends to produce redstools or fresh, bright red blood in the stool, in this case please consult general surgeon at the earliest.