ANSWER:
Hemroids are caused by hard stools (constipation) and/or extreme pressure exerted on the anal canal. Women who have been pregnant experience hemorrhoids quite often.

If you maintain a good diet, especially fruits, grains and fiber in general that will help prevent hemorrhoids. Also, during bowel movements be patient. Just let nature take its course instead of exerting a lot of pressure to speed the process.

A very informative news article was written on the subject at:
http://www.health-news-reports.com/Hemorrhoids/HemorrhoidsHomeTreatment.php
This article very clearly and in detail explains hemorrhoids and lists specific ingredients that are (by testimonies) reputed to provide significant relief.