Hemorrhoids are common colon problems that affect both men and women equally. They can be internal (inside the anus) or external (under the skin around the anus), and occur when the veins around the anus or lower rectum become swollen and inflamed. A common symptom of hemorrhoids is bleeding, including blood in the stool and bleeding from the rectum. Hemorrhoids are often caused by straining during stool movement; but some other factors that can lead to this condition include pregnancy, aging, and chronic constipation or diarrhea. A few ways to prevent hemorrhoids include emptying your bowels as soon as possible after the urge occurs and keeping stools soft -- by increasing fiber in the diet and exercising -- so that they pass easily. Sigmoidoscopy and colonoscopy are among the procedures a healthcare provider may use to diagnose hemorrhoids.