If you do, the chances are that you may get hemorrhoids.

Known commonly as piles, hemorrhoids are swellings of veins in the lower rectum or anus, either internal (above the anal sphincter) or external (outside the sphincter).

Frequently associated with constipation, straining to defecate, pregnancy, or prolonged sitting, hemorrhoids are often painful and sometimes bleed with defecation.

Treatment includes topical agents to shrink and anesthetize the hemorrhoids, compresses, and if severe, ligation or surgical excision.

Dr. Lu Nai-kuan, a Tainan general hospital chief surgeon, said prolonged sitting caused hemorrhoids in young people. "Our patients are getting younger," he lamented. One such patient was an eighth grader.

"He told his mother he was seriously sick because his stool is bloody," Dr. Lu said.

She brought her son to Dr. Lu, who told her the boy has piles because he sat before his computer hours on end every day for close to three years. "That's why the boy got hemorrhoids," Dr. Lu said.