Constipation with bleeding. how do i treat it? what precautions should i take? what foods to avoid?

Constipation: First off, given your age, i would have a colonoscopy done unless you've had it done within the last 10 years and it was normal. Constipation if not caused by malignancy most likely aggravated your hemorrhoids which bleed. In that case, after ruling out other causes, your doc might suggest increase in fluid intake, fiber supplement such as metamucil (helps constipation and bleeding), etc.