Irritable Bowel Syndrome (IBS)
Irritable bowel syndrome (IBS) is a recurrent pattern of abdominal pain that’s often associated with abnormal frequency or form of bowel movements. Some people have hard or infrequent stools; some have loose or frequent ones; and some have both. IBS is not a single disease, nor does it have a single cause. Rather, it involves a constellation of influences that contribute to a pattern of digestive imbalance.
About 3 million office visits annually.
10-15% of the population worldwide have IBS. In America, the breakdown is ~14% of women, ~9% of men.
Varies.
Symptoms
What are common IBS symptoms?
Abdominal discomfort or pain is the primary symptom, either chronic or recurrent. The intensity can range from mild to severe and the character of pain can vary. Many sufferers are most bothered by the inconsistent stool patterns (constipation or diarrhea). Other associated symptoms include flatulence, bloating, stomach rumbling, and a feeling of urgency to get to the bathroom.
Are there other associated conditions?
There are some gastrointestinal (GI) conditions that might overlap with or cause irritable bowels, including gut bacteria imbalances (dysbiosis), infections, enzyme deficiencies, or motility issues like gastroparesis. There are also systemic conditions that more frequently co-occur with IBS. Some examples include fibromyalgia, chronic fatigue, interstitial cystitis, and chronic pelvic pain.
What symptoms make you worry about something more serious?
Some red flag symptoms include unintentional weight loss, bowel movements that interrupt sleep, black-or-red blood in stool, rectal bleeding, a recent change to looser or more frequent stools in those over 60 years old, or family history of bowel or ovarian cancers. I would also include symptoms beyond the intestines--like rashes or joint pains--as possible indicators of a more pernicious and deeper problem.
Diagnosis
What’s the best approach to diagnosis? Is there a test?
To meet IBS diagnostic criteria, abdominal pain should be at least once weekly for three months and have started more than six months ago. That said, irritable bowel and digestive problems can cause significant inconvenience and discomfort, so there’s value in exploring an individual’s symptoms even if they do not meet those set criteria.
Getting a thorough medical history is invaluable for determining patterns of symptoms, possible triggers, and therapeutic starting points. There are some diagnoses that should be ruled out, including celiac disease, malabsorption syndromes, gut infections, and inflammatory bowel disease (Crohns, ulcerative colitis).
This process can lead to an abundance of testing, but it doesn’t have to. History and elimination diet trials also work, especially since testing alone often does not elucidate a clear cause of symptoms.
Does everyone with IBS symptoms need a colonoscopy?
No, the number of colonoscopies performed for IBS can be reduced with thoughtfully sequenced, less interventional tests. (Colonoscopies are more important in older populations with greater colon cancer risk, or if there are red flag symptoms for a possible malignancy.)
Ruling out inflammatory bowel diseases (IBD), such as Crohn’s or ulcerative colitis--which are more severe conditions than IBS and often carry different risks--can be done using blood and fecal tests, specifically the combination of c-reactive protein (CRP) and fecal calprotectin. If those two tests are normal, IBD is essentially not a concern.
Treatment
What is the best approach to IBS treatment?
There isn’t a one-size fits all answer for IBS; ultimately, the best treatment involves an individualized approach.
Dietary elimination trials are an important component of the process. Dairy, gluten, and fermentable short chain carbohydrates, sometimes referred to as FODMAPs, are some of the more commonly implicated offenders. Alcohol consumption is another.
Altering the gut microbiome through diet change, prebiotics, or probiotics is becoming a bigger part of the strategy. Antimicrobial herbs or prescription antibiotics are sometimes utilized, especially for conditions like SIBO, where motility problems and bacterial digestion of foods has caused dominant colon bacteria to translocate to the small intestine.
Serotonin and the other gut neurotransmitters can be manipulated with stress management, proper sleep, and of course prescription medications. The emotional layer can also benefit from cognitive behavioral therapy.
Are there any symptom-specific remedies you’d recommend?
Abdominal pain caused by gas or spasms can be addressed with spices, supplements, or antispasmodic medicines.
Enteric coated peppermint oil capsules are an evidence-based inexpensive supplement that can help with spasm and cramping. Ginger and black pepper can enhance digestion. Constipation can be addressed with hydration, fiber, and other means of improving gut motility.
Loose bowel movements can improve by adding fiber or by slowing gut motility with anti-diarrheal medication, such as OTC Imodium (though this should be used thoughtfully, as it can contribute to other problems with long-term use). Lastly, some people with diarrhea-predominant IBS (IBS-D) have malabsorption and need digestive enzymes.
Is there a “best diet” for IBS?
It’s hard to make broad generalizations for an IBS diet, because foods that cause problems in some (e.g. whole grains, beans, dairy) have also shown positive health outcomes in large population studies. Trigger foods are also a moving target, as intolerances can change for reasons we do not completely understand.
That said, as with other health conditions, avoidance of heavily processed foods is helpful. Also, adequate fiber and polyphenol consumption through vegetables and fruits is important. Lastly, fermented foods seem like a beneficial no-brainer, but in a minority of people, they may fuel the fire.
Under-appreciated in the dietary realm is the importance of why, where, with whom, for how long and how frequently are we eating. Optimal digestion depends not only on nourishing food, but also on all those variables.
How do you tailor individual recommendations?
Unfortunately, there isn’t an easy and accurate way to test for food intolerance. People often have suspicions about triggers, so we work with what we already know--and symptom tracking with a diary can help confirm or disprove those suspicions.
Reduction of common foods, like those on a FODMAPs list, requires someone have a handy list of which foods to avoid. With an elimination trial, at least two weeks are usually required, though up to four-to-six weeks are sometimes recommended, after which re-challenge can be pursued.
Obviously, seeing a beneficial effect from a modification is encouraging, but there may need to be some elimination rotations to see more clear causation of symptoms. In some cases, reduction of intake will have profound benefits, while in others, nearly complete exclusion is necessary.
Understanding IBS
What do we know about the underlying biology for IBS?
At this stage, IBS is known to result from an interplay of microbiota balance, neuroimmune interactions, motility abnormalities, and visceral hypersensitivity. Additionally, stress and other psychological factors have an impact on gut activity, and vice versa. This brain-gut-microbiome axis is an area of active research. Histamine’s role in symptomatology is another emerging player, as increased histamine--produced by certain foods--modifies gut motility and visceral sensitivity.
How is serotonin affected? Does IBS have any connection with antidepressants or depression?
We’re beginning to better understand the enteric nervous system, and thereby the neurotransmitter communication within the gut. Serotonin is present in the intestines–as are serotonin receptors–so there is a real gut-brain connection. We believe this partly explains the increased sensitivity to motility and gas that people with IBS feel.
How does the microbiome tie into this?
Though most of us don’t realize it, we depend on a healthy microbiome for many functions, like production of short-chain fatty acids and certain neurotransmitters. We want rich bacterial diversity in our large intestine, with abundant numbers of the good strains and minimal populations of the strains associated with health problems.
Increasingly, research is looking at the connection between IBS and the microbiome. There is growing evidence that dysbiosis (an imbalance of the gut microbiome) underlies IBS, and that probiotics, prebiotics, symbiotics and dietary manipulation of gut microbiota may help treat IBS.
Do chemical or environmental factors play a role? If so, is there anything that can be done to protect against their impact?
Yes, absolutely, though this is an aspect less often discussed. Certain commonly used medications, like proton pump inhibitors, can change our digestive process.
More concerning though, is our inadvertent consumption of herbicides, pesticides, and other toxins, that–over time–might be compromising the health of our gut ecology. A prudent approach is to try to eat clean, whole foods that don’t require lots of preservatives or additives. The last thing we want is for our nourishment to make us sick.
Is “IBS” something that people have forever?
People can experience tremendous quality-of-life improvements by learning about their particular digestive idiosyncrasies. While some intolerances may never disappear, awareness and attention to them can certainly prevent IBS from controlling one’s life.
Useful Links
Stanford University Low FODMAP diet (Stanford Health Care)
Emerging diagnostics from the Institute of Functional Medicine (Institute for Functional Medicine)
Gut bacteria and IBS (Institute for Functional Medicine)
Connect with our physicians
Jamila Schwartz, MD and Andrew Cunningham, MD are both members of the Galileo Clinical Team. Connect with one of our physicians about Irritable Bowel Syndrome (IBS) or any of the many other conditions we treat.