What Is Peristalsis?

Introduction

Every day, you make a conscious effort to eat food and break it down into bite-sized pieces to make it easier to swallow, but what happens after you swallow the food? Do you ever wonder how the food you swallow gets pushed down your body without conscious effort? This is by a process called peristalsis! 

What is peristalsis?

Peristalsis is the involuntary muscle movement that performs wave-like motions, contracting and relaxing to push contents along your body. 

Mechanism of peristalsis

The biting and chewing of food in the mouth are voluntary responses. In the oesophagus, an involuntary response occurs after swallowing food into the oesophagus:^1,2,3

• Peristalsis is stimulated by swallowing as food enters the oesophagus, a tube surrounded by muscles

• Food is propelled along the oesophagus by a series of contractions and relaxation of muscles within the tube, in a wave-like motion

Similar to the oesophagus, the stomach and the small and large intestines are surrounded by muscles that push the food along by peristalsis. Keep reading to understand in detail how peristalsis is involved in the digestive and other systems. 

Biology of peristalsis and digestive process

• The parasympathetic nervous system stimulates peristalsis by a network of nerves (e.g. like messengers in your body) 
• Our body has a network of nerves that communicate with each other and receive information via signals
• These nerves are stimulated by the stretching of the digestive system or certain chemicals
• This allows the muscle to contract and relax when needed, allowing coordinated movement and the digestive process²

Peristalsis and the digestive system 

Peristalsis occurs in different stages of the digestive process:^4,5

• In the oesophagus, food is pushed from the oesophagus to the stomach by peristalsis to prepare for digestion
• In the stomach, food is blended and mixed with stomach juices (which helps with digestion and absorption), producing a mixture called chyme. Peristalsis contributes to the mixing and enables the progression of chyme to be slowly transported into the small intestine
• In the small intestine, peristalsis moves chyme slowly along the small intestine into the large intestine while the mixing, digestion and absorption of nutrients from the chyme occurs 
• In the large intestine, peristalsis moves chyme along the large intestine while it is further broken down and water is absorbed. Then, peristalsis moves the remaining undigested content and waste products, referred to as faeces, from the large intestine to the rectum

Peristalsis has an essential role in the digestive process and contributes from the start (oesophagus) to the end (rectum) of the digestion process!

Peristalsis and the lymphatic system 

One of the many mechanisms lymph uses to circulate throughout the body is “peristalsis within the lymph capillaries.” 

Peristalsis and the reproductive system

Another example of the peristalsis process is in the reproductive system. In the female reproductive tract, peristalsis (uterine peristalsis) has been found to have a role:^6,7

• during the menstrual cycle
• transporting sperm towards the uterine tube for fertilisation 
• in embryo implantation 

In the male reproductive system, peristalsis contraction occurs during ejaculation: 

• enabling the transportation of spermatozoa (sperm) from the epididymis to the urethra⁸

Peristalsis and the urinary system

Are you wondering how urine goes from your kidneys to your bladder? Yes, via the ureter by peristalsis! This ensures waste products are removed from your body in a timely manner. 

Disorders related to peristalsis

Here are some examples of conditions where peristalsis may be affected by, or peristalsis dysfunction contributes to, the following conditions:^2,9,10

• Achalasia is an example of an oesophageal motility disorder characterised by abnormal peristalsis behaviour
• Gastroparesis
• Gastro-oesophageal reflux disease
• Hirschsprung's disease could result in disrupted peristalsis during bowel movement, leading to difficulty in the passing of faeces 
• Irritable bowel syndrome (IBS)
• Intestinal pseudo-obstruction
• Small intestinal bacterial overgrowth

Symptoms of impaired peristalsis

The following symptoms of impaired peristalsis can include:^2,11

• Dysphagia (problems with swallowing)
• Chest pain 
• Constipation 
• Diarrhoea 
• Heartburn 
• Regurgitation
• Vomiting 
• Weight loss 

Dietary influences 

• Some examples of dietary influences include fibre intake and hydration
• Fibre intake can stimulate peristalsis in the intestine, improving bowel movement and defaecation habits and relieving constipation¹²

Drinking plenty of water and keeping hydrated can soften faeces and prevent constipation.¹³

To know more about keeping a healthy digestive system, refer to this article: ‘How Can I Heal My Digestive System Naturally?’

Lifestyle factors 

• Some examples of lifestyle factors include physical activity and psychological stress
• Physical activity stimulates intestinal peristalsis and prevents constipation^13,14,15
• Psychological stress may induce bowel dysfunction and affect bowel habits¹⁶

FAQ

What is peristalsis? 

A type of involuntary muscle movement that pushes content along the body in a wave-like motion. 

What is peristalsis in digestion? 

Peristalsis is a type of muscle movement that occurs within your body to move food content along your body for digestion. 

Does peristalsis weaken with age? 

Yes, there is an association between weakened peristalsis and an increase in age.¹⁷

Summary 

In summary, peristalsis is an involuntary muscle movement that moves content along your body and is a process that occurs in organ systems such asdigestive, reproductive, urinary and lymphatic. The most common example of peristalsis is in the digestive system, which uses peristalsis from the very start of the digestive process to the end - from the oesophagus to the rectum. This article lists some disorders that affect peristalsis or contribute to the process. Moreover, we list some important dietary influences and lifestyle factors that may stimulate peristalsis or result in bowel habit changes.