What’s the Connection Between IBS and Restless Leg Syndrome?

People who have irritable bowel syndrome (IBS), a disorder that affects the gut, have a higher chance of also being diagnosed with restless leg syndrome (RLS), a nervous system condition.

About 10 percent of people in the United States have RLS, according to the National Institutes of Health, and as many as 15 percent have IBS, the American College of Gastroenterology reports.

A meta-analysis published in January 2021 in the journal Sleep Medicine, looked at five observational studies that together included more than 86,000 people whose IBS appeared to predict RLS. Compared with the general population, patients with IBS had a nearly threefold increased risk of having RLS.

Although the two conditions are not directly related, and one does not cause the other, IBS and RLS do share commonalities related to how the brain interprets sensation.

According to Xiao Jing Wang, MD, a gastroenterologist at Mayo Clinic in Rochester, Minnesota, both IBS and RLS are central sensitization syndromes, a group of conditions that include IBS and RLS, as well as fibromyalgia, migraines, and chronic fatigue. In all of these conditions, a person’s brain or nervous system is more sensitive to sensations, including pain.

“For people with IBS, their bowels feel more than people without this sensitivity,” Dr. Wang says. “Similarly, with RLS, patients are more sensitive to feelings in their limbs. If you are pricking someone with RLS, they are going to feel way more than someone without RLS.”

That amplification of painful or uncomfortable sensations is something people with RLS and IBS may have in common, according to Yuying Luo, MD, chief gastroenterology fellow at Mount Sinai Hospital in New York. Pain from one condition can drive sensitivity to pain from the other, says Wang.

Despite their names, both conditions affect more than a single body system.

“Although there's still a lot we don't know about the condition, IBS is now conceptualized as a disorder of the gut-brain interaction,” she says. “This means that IBS is not just a disorder isolated to the gastrointestinal tract, there is a two-way link between the GI tract and the nervous system.”

The Nervous System Link

According to the National Institute of Neurological Disorders and Stroke, RLS is a neurological disorder — meaning one that affects the nerves — that causes uncomfortable sensations in the legs, which triggers an irresistible urge to move them.

Research has shown that having IBS puts a person at higher risk of developing other pain and neurological disorders, too.

In a study published in February 2023 in the journal Neurogastroenterology & Motility, Wang and her colleagues collected survey data from 775 people with a central sensitization syndrome diagnosis. Of those, 264 — about 35 percent — reported having IBS. Only 3 percent of IBS patients reported having only IBS and no other central sensitization syndromes.

Nearly 75 percent of people with IBS also reported migraines, and just over half reported IBS and fibromyalgia — both which are conditions that affect the nervous system. They also found that having multiple central sensitization syndrome disorders increases the severity of symptoms.

Symptom-Based Disorders

Both IBS and RLS are diagnosed based on a person’s symptoms, since there aren’t blood-based tests or imaging that can diagnose either condition, according to Dr. Luo.

IBS in particular can impact people in very different ways. Symptoms can include abdominal pain or cramping, frequent bowel movements, gas or mucus in the stool, bloating, as well as diarrhea, constipation, or a mix of both, according to Mayo Clinic.

RLS causes the irresistible urge to move and uncomfortable sensations in the lower limbs. People may feel an aching, throbbing, pulling, itching, crawling, or creeping sensation in their lower limbs. Although it’s less common, the sensations can also affect the arms, chest or head, and usually affect both sides of the body, according to the National Institutes of Health.

"The disorders are pretty different based on symptom presentation," Lou says. "They shouldn’t be confused by each other, but it’s important for physicians to be aware that in their IBS patients, RLS might be more common and vice versa."

Overlapping Treatments

One reason it’s important to know if you have both IBS and RLS is that some treatments for IBS symptoms can actually worsen symptoms of RLS.

According to Luo, neuromodulators — medications that alter nerve activity, and the impulses they send to the brain — including one used to treat abdominal pain in IBS, called tricyclic antidepressants (TCAs), may exacerbate RLS symptoms.

"Nonpharmacological approaches may be helpful to address both conditions," she says, noting that there is some evidence that suggests exercises such as yoga can help both IBS and RLS symptoms.

Other therapies including cognitive behavioral therapy (CBT) and transcutaneous electrical nerve stimulation (TENS), a therapy that uses low voltage electrical current to relieve pain, have also been shown to be effective treatments for both IBS and RLS symptoms, according to Luo.

In a small randomized controlled trial, published in January 2020 in the Journal of Clinical Sleep Medicine, 13 people with RLS completed a 12-week yoga course while 17 spent those 12 weeks learning about RLS through educational films. After the 12 weeks were up, both groups reported significant improvements in RLS symptoms and the severity of their symptoms, as well as perceived stress, mood, and quality of life. However, the yoga group reported a significantly greater improvement over those in the film group.

A small randomized clinical trial, published in February 2023 in The American Journal of Gastroenterology, looked at whether or not virtual yoga classes that focused on breathwork, mindfulness, and physical activity could improve IBS symptoms. Nearly 80 adults with an average age of about 45 years were split into two groups: Half attended virtual yoga classes for eight weeks and the other half watched a 10-minute video that included general education on IBS, the role of the mind-gut connection in the condition, and the role of mind-body therapies in IBS management. The second group also received a list of IBS-related resources from the Canadian Digestive Health Foundation, a link to an IBS patient support group, and information about physical activity guidelines from the World Health Organization (WHO).

After eight weeks, each person was asked to fill out a survey regarding their IBS symptoms as well as mental health. Each item was assigned a point value and the researchers considered any improvement of 50 points or more to be significant. Compared with the yoga group, about half as many people in the control group, the ones who watched the video, reported a significant decrease in symptoms.

Research May Reveal Root Cause

Wang says that although experts are still teasing out which biological factors cause both RLS and IBS, there is a lot of research being done to investigate how neurobiology, the gut microbiome, and even the mucus lining in the gut may determine whether or not a person develops both IBS and RLS.

“It’s important for patients to know that the research confirms that these are real disorders and that they are biologically driven, but we are not at the point where we can detect it clinically yet,” she says.