Hemorrhoids are large blood vessels at the end of the intestinal tract.
Recent medical breakthroughs show that procedures widening the sphincter or a nitroglycerin ointment may be more effective treatments than surgical removal of the hemorrhoids. Hemorrhoids cause pain or bleeding. They are associated with constpation, pregnancy and irritable bowel syndrome, a condition characterized by gas and cramping. Most doctors think that hemorrhoids are caused by a tight sphincter that squeezes the arteries and veins as they carry blood to and from the last part of the intestines. Since pressure in arteries is much greater than that in veins, the arteries remain open, while the veins collapse, increasing pressure in the veins and causing them to widen, hurt and bleed.