If you’ve been treating your acid reflux like it’s simply a problem of “too much acid,” you’re not alone. But in many cases, it’s not actually about how much acid you have. It’s about how well your digestive system is moving.
In this post, we’re diving into the often-overlooked world of gut motility, the rhythmic muscle contractions that move food through your digestive tract. Most people associate slow digestion with constipation, but when this system slows down, it can also set the stage for acid reflux.
How Slow Gut Movement Fuels Reflux
Delayed stomach emptying and constipation don’t just cause bloating or discomfort; they can also increase pressure in the gut. That pressure can push stomach contents back up through the lower esophageal sphincter (LES), the “trapdoor” that normally keeps acid in the stomach where it belongs.
When food lingers in the stomach or intestines too long, fermentation and gas production increase, which in turn increases pressure on the stomach. This elevated pressure can weaken the LES over time, making it easier for stomach contents to escape upward.
The Addiction and Mental Health Connection
Addiction and mental health conditions don’t just affect the brain; they can significantly impact gut function as well. From slowing digestion to increasing the risk of bacterial overgrowth, these factors can directly disrupt motility and contribute to symptoms like bloating, constipation, and acid reflux.
- Alcohol can interfere with the nervous system’s regulation of digestion and impair gut motility. It is also a well-established risk factor for developing small intestinal bacterial overgrowth (SIBO) (5). The condition increases gas and bloating, which in turn raises intra-abdominal pressure and the risk of reflux. (We’ll explore this more later in the post.)
- Opioids, whether used short- or long-term, are a well-documented cause of slowed gut motility and constipation. Over 40 percent of patients taking opioids experience constipation. Research also shows that opioids can delay gastric emptying and contribute to esophageal dysfunction (4), both of which may directly worsen GERD symptoms.
- Mental health is intimately tied to gut motility — not just due to stress. Studies show that individuals with conditions such as anxiety and depression are significantly more likely to experience delayed gastric emptying and functional gastrointestinal disorders (2)(3).
Constipation: The Silent Driver of Acid Reflux
Think of your GI tract like a traffic system. When there’s a pileup in the colon, it causes backups all the way to the stomach. Constipation doesn’t just cause discomfort; it increases intra-abdominal pressure, forcing stomach contents upward.
In fact, evidence supports the use of a high-fiber diet for managing GERD (6)(7)(8). One study found that treating constipation with psyllium seed fiber significantly improved GERD symptoms (9), not by reducing acid, but by enhancing elimination and relieving intra-abdominal pressure.
When IBS and Reflux Collide
If you deal with IBS symptoms like gas, bloating, diarrhea, constipation, or a mix of all three, there’s a chance you could have something called SIBO (small intestinal bacterial overgrowth). SIBO can worsen reflux by increasing gas production and bloating, which raises intra-abdominal pressure. This pressure can push stomach contents upward, making reflux more likely. There is substantial evidence supporting the idea that SIBO can cause or exacerbate GERD (10–13), and that treating SIBO can, in some cases, resolve GERD symptoms (14–15).
However, SIBO isn’t always the root cause. It’s possible that both SIBO (16) and reflux (18-19) arise from the same underlying issue: slow gut motility. To complicate matters further, the most commonly used medications for treating reflux, such as proton pump inhibitors (PPIs), have been shown to increase the risk of developing SIBO (20) and delay gastric emptying (17). In other words, your reflux treatment might be contributing to the very condition that worsens your reflux.
Clues That Your Gut Motility Is Off
Gut motility issues can show up in different ways, but common red flags include:
- Bloating and gas
- Frequent burping
- Feeling full quickly or like food “just sits” in your stomach
- Still feeling full long after eating
- Alternating between constipation and loose stools
- Nausea
- A history of diabetes, thyroid disorders, or vagus nerve dysfunction
Some people may also be dealing with gastroparesis, a more severe delay in stomach emptying.
How Nutrients and Neurotransmitters Influence Digestion
Motility isn’t just mechanical; it’s also deeply connected to your nervous system and biochemistry.
- Vitamin B12 is essential for healthy nerve conduction. Low levels of B12 have been strongly associated with gastroparesis, especially in people with diabetes (21), but B12 deficiency can also slow gut motility in general by impairing nerve and muscle function in the digestive tract.
- Chronic stress is known to cause or worsen reflux through multiple mechanisms, including its impact on gut motility (22)(23).
- Serotonin, a key neurotransmitter, plays a central role in regulating gut movement. In fact, most of your body’s serotonin is produced in the gut — not the brain. Before we knew about SIBO, it was very common for doctors to prescribe antidepressants, including SSRIs, for people with IBS. That’s because serotonin doesn’t just affect mood and anxiety; it also helps stimulate motility. In one study on mice, supplementing with 5-HTP (a precursor to serotonin) led to increased gut motility (24).
- Melatonin, which is synthesized from serotonin, also plays a role in regulating gut motility (25). Interestingly, the gut contains about 400 times more melatonin than the pineal gland, the part of the brain responsible for regulating sleep. Supplementing with melatonin has been shown to improve GERD symptoms (26).
So if you’re stressed, low in B12, or dealing with anxiety or mood disorders, your digestive tract may be moving at half speed, making reflux worse.
Natural Ways to Get Things Moving Again
Many people find lasting relief by supporting the body’s natural motility mechanisms. The best approach begins with foundational lifestyle changes and gradually incorporates targeted support, only resorting to supplements or medications if needed.
If you experience acid reflux along with constipation or other signs of slow motility (like bloating, early fullness, or gas), these natural strategies may be good starting points to address the root causes rather than just symptoms.
1. Dietary & Lifestyle Strategies – Start with the Basics
Before reaching for supplements, it’s important to build a solid foundation. These strategies are safe, sustainable, and essential for digestive function:
Fiber: Boosts motility and supports a healthy microbiome. Aim for a balance of:
- Soluble fiber from fruits and vegetables
- Insoluble fiber from whole grains and seeds
- Hydration: Dehydration is a major contributor to constipation. Increase water intake—especially when adding fiber.
Movement & Exercise: Regular activity (e.g., walking, yoga, light cardio) stimulates intestinal contractions and keeps things moving.
Stress Management: Practices like deep breathing, vagal toning exercises, acupuncture, and walking after meals activate the parasympathetic nervous system, which enhances motility.
Why start here? These changes benefit nearly every system in the body—not just digestion—and are low-cost, low-risk steps with high payoff.
2. Digestive Bitters – Simple, Natural Stimulation
Bitters are herbs that trigger digestive secretions and vagus nerve activation when taken before meals. They support:
- Gastric acid production
- Bile flow
- Enzyme release
- Peristalsis (gut motility)
Common bitters: gentian root, artichoke leaf (31-33), dandelion, ginger (27-30)
Natural food sources: arugula, watercress, endive, radicchio, ginger (27-30)
Note: Avoid bitter supplements if you have gallstones or a bile duct obstruction. Bitters from foods are generally safe.
Why now? Incorporating bitter foods like 1–2 cups of dark leafy greens daily, and adding in ginger tea or ginger shots, can go a long way in supporting gut motility and overall health. Start there before trying supplements (unless otherwise advised by your healthcare provider).
3. Probiotics – Rebalancing the Gut-Brain Axis
Gut flora and motility are deeply intertwined. Dysbiosis (imbalanced gut bacteria) can reduce motility, and slow motility can worsen dysbiosis. Probiotics can help interrupt this cycle. Recommended options:
- Saccharomyces boulardii – A beneficial yeast that reduces inflammation and supports gut lining integrity; helpful post-antibiotics or post-SIBO (34)(35).
- Spore-based probiotics – Resilient strains ideal for those with SIBO or sensitive digestion (36-38).
- Seed Daily Synbiotic – Combines prebiotics with 24 well-researched strains to support microbiome diversity and motility.
Why third? Once digestion is supported and diet is dialed in, probiotics can help restore balance and prevent recurrence of symptoms.
4. Magnesium & Fiber Supplements – Constipation Support
For people who remain constipated despite steps 1–3, certain supplements can offer effective, low-risk support:
- Magnesium citrate or magnesium oxide: These forms draw water into the colon and promote bowel movements. At least roughly 60 percent of Americans are magnesium deficient, so supplementation may also support muscle function, mood, and sleep.
- Fiber supplements:
- Psyllium husk and citrus pectin are excellent for adding bulk and supporting gut flora.
- Citrucel (methylcellulose) is a well-tolerated option for those who don’t do well with standard fiber supplements.
Why now? When there’s any degree of constipation, these are foundational add-ons to consider. These targeted tools support motility when food-based strategies and probiotics aren’t quite enough.
5. Prokinetics – Reserved for When More Help Is Needed
Prokinetics are agents that directly stimulate the muscular contractions (peristalsis) that move food through the digestive tract. They’re often used when other strategies aren’t fully effective.
Natural options include:
- Iberogast – A blend of herbs (including bitter candytuft, chamomile, and licorice) shown in multiple studies to support gastric emptying and reduce reflux (1)(42).
- MotilPro and Prokine – Contains 5-HTP, ginger, and B vitamins to support serotonin-mediated motility.
- Motility Activator and Motility Pro – Drug-free blends of ginger and artichoke extract that enhance upper GI motility.
Caution: If you’re taking medications that affect serotonin, speak with your doctor before using products with 5-HTP.
Why last? Prokinetics can be highly effective but should be reserved for when foundational strategies aren’t enough—either due to underlying gut-brain signaling dysfunction, after SIBO treatment, and/or stubborn constipation.
Note on Dyssynergic Defecation (DD): Before attributing constipation solely to impaired motility, it is essential to rule out dyssynergic defecation. The condition is caused by poor coordination or inadequate strength of the pelvic floor muscles. In several studies, DD was identified as the underlying cause in approximately 35–50 percent of constipation cases (40)(41). This form of constipation responds best to treatment by a physical therapist specializing in pelvic floor therapy, often incorporating biofeedback techniques. In fact, a meta-analysis found that biofeedback was more than three times as effective for treating DD compared to fiber, laxatives, or prescription medications (39).
Bottom Line
If your reflux hasn’t improved with acid-suppressing medications, or if symptoms return as soon as you stop them, it’s time to zoom out. Motility disorders like constipation, IBS, SIBO, and delayed gastric emptying are often hidden contributors to reflux. By addressing gut movement, nutrient status, and stress, you’re more likely to see lasting relief.
In our next post, we’ll explore how bile flow and gallbladder health impact GERD, and what to do when bile, not acid, is the real problem.
