have a cough which hurts my chest, constant blocking of the nose, sometimes with yellow mucus, fever of 100.5, but what worries me the most the last two days are my very dark bowel movements. i have constipation and huge haemerrhoids and i take psilium one teaspoon in the evening and then about an hour later drink say a gallon of water and of course my bowels then come flowing out. but now, they turned black.