The condition is receiving greater attention and research, but is still widely misunderstood
Irritable bowel syndrome (IBS) is the term given to a group of symptoms that occur causing abdominal pain, changes in your bowel habits, or both—but without any specific cause or evident underlying damage. Affecting the large intestine, the condition does not have a defined or even typical set of symptoms, which is one reason why those who suffer from IBS may cite a wide variety of symptoms.
In this article, we attempt to clarify some common misconceptions on IBS, while revealing some recent research that hopes to bring relief to those who suffer from the condition.
It’s more common than you might think. It’s believed that as much as 15 percent of people in the developed world suffer from symptoms of IBS. The condition is especially prevalent in South America. A 2015 JAMA article summarized a number of characteristics of the condition in greater detail. A few of the highlights:
- IBS is twice as common in women as it is in men
- Onset typically occurs before age 45, and becomes gradually less common with age. Due in part to those factors, onset of IBS after age 50 tends to draw a particular amount of attention from doctors
- IBS does not impact life expectancy, nor does it indicate or lead to other, more serious diseases
- While the condition itself has likely been around since the dawn of time, the first description is less than two centuries old (1820, according to one publication) and the first use of the term “irritable bowel syndrome” is believed to have occurred during the World War II era
Classifications. Some experts divide or classify IBS by the prevalence of symptoms as follows:
- IBS-D (diarrhea is common)
- IBS-C (constipation is common)
- IBS-M (both diarrhea and constipation are persistent)
- IBS-U (neither of the two symptoms are particularly prevalent)
Causes are unclear, and there is no known cure. Any identified causes are based purely on theoretical study. Some of those theories include gut disorders, gut-brain interactions, infections such as small intestinal bacterial overgrowth, or even sensitivity to food. Onset is commonly associated with intestinal infection or a stressful life event.
As indicated in the previous section, doctors find onset of IBS past the age of 50 to be a particularly worrisome factor. Weight loss, blood in the stool or prolonged family history of IBS are similarly concerning. Diagnosis, in the absence of these worrisome factors, is based solely on the presence of symptoms.
Treatment/Management. With no known, established cure, the focus turns to treating and managing IBS to lessen or eradicate the harmful symptoms. Research and discovery of effective methods of management continue; for now, here are a few of the better-known, more effective approaches.
A diet low in FODMAPs has led to an easing in symptoms in up to 70 percent of patients. FODMAPs, short for Fermentable Oligo-, Di-, Mono-saccharides And Polyols, and characterized as carbohydrates that are poorly absorbed by the small intestine. Fructose and lactose are the ‘stars’ of this group, but the full list contains many foods that are staples of the Western diet, including several that are otherwise considered part of a healthy diet. Individuals with IBS are therefore advised to avoid or limit intake of these foods.
So what foods should be eaten if avoiding FODMAPS? Proteins, specifically fish and chicken, are on the ‘safe’ list, as are almonds and gluten-free breads and pasta. Recommended fruits and vegetables include oranges, grapes, lettuce and tomatoes.
At least one national guideline suggests switching to a diet low in FODMAPs only when other lifestyle and dietary modifications have proven ineffective. The diet low in FODMAPS have been known to specifically impact symptoms such as urgency, bloating, and flatulence.
Evidence surrounding fiber supplements is mixed, with some reporting improved stool consistency while others complain that supplementation agitates the condition and worsens symptoms.
Medications largely consists of stool softeners and laxatives for cases where constipation is persistent, and anti-diarrhea medicines for cases where diarrhea is the predominant symptom.
Current Research
In the beginning of this article, we cited the statistic indicating IBS is twice as common in women as it is in men. Recent discoveries may go a long way towards explaining that anomaly, and hopefully provide some insight into whether there are means of counteracting any genetic predisposition to the condition.
“Although we cannot point to individual genes at this early stage, we believe these results are exciting, as they converge with existing data on female preponderance and a role of sex-hormones in IBS,” said Mauro D’Amato, PhD, a visiting professor in the Department of Medicine at Karolinska Institutet in Solna, Sweden.
The genetic factors, while well known, have received remarkably limited research into their causes or contributing factors. Dr. D’Amato and his cohorts studied over 500,000 participants’ genetic data to determine the increased risk for IBS was significantly associated with genetic variants on chromosome 9—specifically in a region previously associated with age of first menstruation. The findings, experts say, support further study into the link between sex hormones and IBS.
“Exploiting the large U.K. Biobank resource, as well as several patient cohorts from European and U.S. expert centers, we have been able to study genetic predisposition to IBS with increased statistical power, better than ever before,” Dr. D’Amato said in a press release.
