The numbers, however, are based on a study conducted all the way back in 1984. As a result we do not really know how many South Africans currently suffer from IBS.
Despite being a common problem, IBS, or spastic colon, is tricky to diagnose.
The help of an acoustic belt
A belt that wraps around your stomach and "listens" for the telltale sounds of irritable bowel syndrome (IBS) may make it easier to spot the notoriously elusive disease.
"IBS is difficult to diagnose because it affects the function of the gut, rather than causing an obvious physical change," explained study lead researcher Barry Marshall. He's professor and director of the Marshall Centre for Infectious Diseases Research and Training at the University of Western Australia.
Doctors are often forced to use either time-consuming or unreliable questionnaires that look for symptoms, or invasive colonoscopies. IBS symptoms can include stomach pain, bloating, and diarrhoea and/or constipation.
"These [methods] are costly, uncomfortable and carry risks," Marshall said, "and yet still don't provide a positive diagnosis of IBS. Patients are left confused and feeling not taken seriously by doctors."
The acoustic belt aims to change all that.
IBS medical check
"When encountering a patient with possible IBS, [doctors] would first check them for red flags for physical diseases," Marshall noted. "Then send them off to wear our belt. A positive result with the belt would give confidence in the IBS diagnosis, so that both doctor and patients can get started on treatment."
Meanwhile, additional blood tests could be deployed to rule out other potential problems.
Early "proof-of-concept" testing indicates "that it is possible to differentiate between IBS patients and people with healthy guts with 87% accuracy," Marshall said.
In 2005, Marshall was awarded the Nobel Prize for his ground-breaking efforts to unearth a bacterial smoking gun for both stomach ulcers and stomach cancer.
Marshall's latest research centres on IBS, which is estimated to affect roughly 11% of all men and women.
His team noted that the technology harnessed by the acoustic belt was initially designed to track munching sounds emanating from termites.
In the study, the belt was tested on healthy individuals and patients already diagnosed with IBS.
Participants wore the belts for about two hours after fasting, and then again for about 40 minutes following a meal.
Among a first pool of 68 participants, the belt proved about 90% accurate in distinguishing IBS. Among the second pool of 30 participants, the belt proved about 87% accurate.
The way forward
"The next step," said Marshall, "is to work with product developers on a more refined and robust prototype belt. We will be testing this in clinical settings early next year," with the goal to bring the belt to market by 2021.
Dr Andrea Shin, an assistant professor in the division of gastroenterology and hepatology at Indiana University's School of Medicine, said the belt approach "is interesting and could be helpful in assessing gut function through an approach that does not rely entirely on an individual's description of their symptom patterns." She was not involved with the study.
But going forward, Shin said that "it would also be helpful to know if bowel sounds varied based on symptom severity in patients with IBS. For example, can the acoustics discriminate those IBS patients who are and are not experiencing a flare of their symptoms?"
And noting that "symptoms can be extremely variable from person to person," Shin also suggested that follow-up research should focus on different types of IBS patients, such as those with diarrhoea versus patients with constipation
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