You may have heard that sleeping on your left side is better for digestion, especially if you deal with heartburn, bloating or chronic gut issues. This advice is not just folklore. The position of your body during sleep can influence how your digestive system behaves once you lie down.
How left-side sleeping supports digestion
The primary reason left-side sleeping is linked to better digestion comes down to anatomy and gravity. When you lie on your left side, your esophagus sits higher than the point where it connects to the stomach, known as the lower esophageal sphincter (LES).
According to Keith C. Summa, a gastroenterologist at Northwestern Medicine, this positioning makes it harder for acidic stomach contents to flow back into the esophagus. Gravity helps keep stomach acid where it belongs and, if reflux does occur, allows it to drain back into the stomach more quickly.
This is particularly relevant for people with gastroesophageal reflux disease (GERD). Research has shown that left-side sleeping is associated with fewer reflux episodes compared with sleeping on the back or right side.
Left-side sleeping and acid reflux relief
Multiple clinical studies have found that people with nighttime GERD symptoms experience fewer and shorter reflux episodes when sleeping on their left side. A recent clinical trial found that encouraging left-side sleeping led to more reflux-free nights and reduced symptom severity.
Sleeping on the right side or flat on the back places the stomach in a position where acid can more easily move upward into the esophagus, increasing the likelihood of heartburn and nighttime discomfort.
How it helps with gas and bloating
Left-side sleeping may also help reduce bloating and gas. The stomach often contains a gas bubble above partially digested food. When lying on the left side, this gas is more likely to move upward and be released through belching, reducing pressure and abdominal discomfort.
For people who frequently wake up feeling bloated, this position may provide noticeable relief.
Does left-side sleeping improve digestion speed?
Some researchers suggest that left-side sleeping may help food move more efficiently from the stomach into the small intestine due to how these organs are positioned relative to each other. While this theory is biologically plausible, strong clinical evidence is still limited.
Even so, reduced reflux and gas alone can significantly improve nighttime digestive comfort.
Are there any downsides to side sleeping?
From a digestive standpoint, there are no known downsides to sleeping on your side. However, some people experience shoulder or neck discomfort, particularly if their pillow does not properly support spinal alignment.
Using a pillow that keeps your head, neck and spine in a neutral position can help reduce joint strain and improve overall sleep quality.
What happens if you sleep on your back?
Sleeping on your back can make reflux symptoms worse. In this position, the esophagus may sit lower than the stomach, allowing gravity to pull stomach acid upward. Back sleeping can also worsen snoring and sleep apnea in some individuals.
If back sleeping is unavoidable, elevating your upper body at a 30–45 degree angle using pillows or by raising the head of the bed may help reduce reflux.
Is stomach sleeping good for digestion?
Research on stomach sleeping and digestion is limited. However, lying flat in any position may worsen bloating and reflux symptoms. For people with digestive complaints, experts generally recommend left-side sleeping or sleeping at an incline rather than lying flat on the stomach.
Best sleeping position for inflammatory bowel disease (IBD)
People with inflammatory bowel disease, including Crohn’s disease and ulcerative colitis, often struggle with poor sleep quality. The relationship between gut inflammation and sleep disruption appears to be bidirectional.
Dr. Summa notes that while it is unclear whether sleep problems worsen IBD or vice versa, maintaining consistent sleep habits, avoiding late meals and sleeping on the left side may help reduce nighttime symptoms and improve rest.
Eating before bed and digestion
Large meals close to bedtime can worsen reflux regardless of sleep position. After eating, the stomach continues producing acid for hours. Lying down too soon removes the benefit of gravity, increasing the risk of acid reflux.
Experts generally recommend waiting at least two hours, and preferably three hours, between your last meal and bedtime to support digestion and reduce nighttime heartburn.
Circadian rhythm and digestive health
Digestion is closely tied to your circadian rhythm, the body’s internal 24-hour clock. Disrupted sleep schedules can interfere with gut function, hormone release and metabolic regulation.
Maintaining consistent sleep and meal times helps align your digestive system with your circadian rhythm, improving overall gut function and reducing the risk of digestive disorders.
Key takeaways
If you do not experience heartburn or digestive discomfort, sleep position may not make a noticeable difference. However, for people with GERD, frequent bloating or inflammatory bowel disease, sleeping on the left side is a simple, low-risk habit worth trying.
Left-side sleeping supports gravity-assisted digestion, reduces acid reflux, helps relieve gas and may improve nighttime gut comfort. Combined with consistent sleep schedules and avoiding late meals, it can play a meaningful role in supporting digestive health.
