Emerging and Ongoing Research on IBS
Despite all the information available about IBS, there is still a lot left to discover. Research is being conducted by clinicians and scientists to answer many of the questions that still exist about IBS and to find ways to better diagnose, manage, and improve IBS symptoms.
To date, IBS is typically diagnosed clinically based on the definition provided by the American College of Gastroenterology, which simply states IBS as abdominal pain with disordered bowel movements. However, this definition still has not yet been validated.1
There is currently no gold standard diagnostic method for IBS. Instead, there are several sets of symptom-based guidelines that may be used to correctly diagnose IBS. The detailed guidelines are the Manning criteria and the Rome III criteria. The Rome III criteria are not commonly used in clinical practice but are frequently used in research studies. A new Rome IV diagnostic criteria should be coming out in Spring 2016. However, the new criteria will still need to be validated through clinical research studies and in everyday practice.1
Lifestyle modification, including exercise, may improve IBS symptoms. Results from a recent study showed that physical activity of 20-60 minutes of moderate to vigorous exertion 3 times a week for 12 weeks resulted in a significant reduction in IBS symptoms compared to inactivity. Other studies suggest adequate sleep and stress management may improve IBS symptoms.1
There have been recent studies on the effect of food on IBS symptoms. In particular, studies on gluten showed that a gluten-free diet in people with diarrhea-predominant IBS, and without celiac disease, resulted in reduced bowel movement frequency after 4 weeks. In addition, there is ongoing research on the effect of a low-FODMAP diet. FODMAPs are fermentable oligosaccharides, disaccharides, monosaccharides, and polyols found in the diet, such as fructose. Preliminary results show that a low-FODMAP diet had a significant improvement on IBS symptoms.1
There is ongoing research to learn about the benefits of probiotics. Probiotics are thought to modify the bacterial environment in the gut, which may improve the gut’s ability to function as a barrier to toxins and harmful microorganisms. The most-studied probiotic is B. infantis, which was shown to improve abdominal symptoms, including bloating and bowel function.1
There is one emerging therapy for diarrhea-predominant IBS, called eluxadoline. It has been studied to determine improvements in abdominal pain and stool consistency over a 12 week period. Eluxadoline was more effective than placebo in improving abdominal pain and stool consistency for at least 50% of the days during the 12-week treatment period.1
There are several emerging therapies for constipation-predominant IBS. Elobixibat is a bile acid modulator, which ultimately increases the amount of bile acids entering the colon to relieve constipation. Studies have shown an improvement in the number of bowel movements, loosened stool consistency, and decreased straining.1
Another emerging therapy is plecanatide. Preliminary results show improvements in constipation symptoms, including abdominal pain and bowel habits over a 12-week period. Improvements in bowel movements were also found with tenapanor, a new therapy that showed complete spontaneous bowel movements.1
Additional areas of research
Research is still needed to focus on the relationship roles of intestinal permeability, immune activation, and the gut environment in learning more about what causes IBS. It will be interesting to find out about how these factors relate to the movement of food through the intestines and any sensitivity issues.1
- Lacy BE, Chey WD, Lembo AJ. New and emerging treatment options for irritable bowel syndrome. Gastroenterol Hepatol (N Y). 2015;11(4 Suppl 2):1-19.