
According to statistics from the National Institute of Diabetes and Digestive and Kidney Diseases, one in 10 Americans develops an ulcer at some time in his or her life. Moreover, about 6,000 Americans die of stomach ulcer-related complications every year.
Rajapaksa said the most common cause of ulcers is infection with a common bacterium known as H. pylori. But she added that the long-term use of aspirin, ibuprofen and other NSAID, or non-steroidal anti-inflammatory drugs, can also lead to an ulcer.
"These medicines can damage the lining of the stomach," she said.
A vast number of people use over-the-counter NSAIDs on a regular basis, and patients recovering from certain procedures may take these drugs in larger doses. In 1999, Barbara Bush underwent elective back surgery; however, at the time her family did not clarify the exact nature of her surgery.
Still, Peters said it was likely that the painkillers she received while recovering from this surgery, as well as any other similar drugs that she has taken since, contributed to her ulcer.
"There is a high proportion of the population in her age group that is on NSAIDs," he said. "Probably this is the most likely underlying cause ... Eighty percent of ulcers are caused either from chemical irritation or H. pylori."
Rajapaksa said that cancer is also a common concern among doctors when dealing with a perforated ulcer. But she added that in Barbara Bush's case, it is unlikely that cancer was the underlying cause of her condition.
"Certainly there is always the possibility of cancer," Rajapaksa said. "However, in this case it probably wouldn't have been repaired in this way, endoscopically, if it had been cancer."
Thus far, Barbara Bush's only documented brush with cancer was the removal of a small cancerous growth from her upper lip in February of 1990.
Barbara Bush has sought medical attention in the past for a number of other issues as well. In 1989, a thyroid condition known as Graves disease reportedly caused her to lose 18 pounds in three months. She later began taking medication and in 1990 received radiation therapy for her eyes as part of her treatment for this condition.