Gastrointestinal motility disorders are conditions that disrupt the normal movement of food and waste through your digestive system, affecting how your body processes what you eat and how comfortable you feel throughout the day.

What Are Gastrointestinal Motility Disorders?

Gastrointestinal motility disorders are digestive problems that happen when the nerves or muscles of the gut do not work together in a coordinated way. The term motility refers to the contraction of muscles that mix and move contents through the gastrointestinal tract, from the mouth all the way through the digestive system and out of the body.^[1][2]

When a person has a motility disorder, their body’s ability to move food along the digestive tract becomes impaired. This can happen in any part of the digestive system, from the throat and esophagus down to the stomach, intestines, and rectum. Some disorders affect only one section, while others may involve multiple areas or even progress to affect more parts of the digestive tract over time.^[2]

The digestive system relies on a complex network of muscles and nerves to function properly. Muscles push food along through a wave-like motion called peristalsis, which is the progressive contraction and relaxation of the muscular gut tube. The enteric nervous system, often called the “second brain” because it contains the second-largest number of neurons in the body after the brain itself, controls this movement along with regulating secretion and sensation within the gut.^[8][14]

Types of Gastrointestinal Motility Disorders

Doctors typically divide motility disorders based on which part of the digestive system they affect. The upper gastrointestinal tract includes the esophagus and stomach, while the lower part includes the intestines and colon.^[6]

Upper gastrointestinal motility disorders include conditions like achalasia, which involves a loss of esophageal peristalsis with failure of the lower esophageal sphincter to relax properly. Gastroesophageal reflux disease (GERD) causes stomach contents to flow backward into the esophagus, resulting in symptoms or damage to the esophageal lining. Gastroparesis is characterized by delayed gastric emptying without any mechanical blockage, causing symptoms like nausea, vomiting, early fullness when eating, and abdominal pain.^[6][12]

Lower gastrointestinal motility disorders affect the intestines and include conditions such as irritable bowel syndrome (IBS), which presents as chronic abdominal pain with changes in bowel habits without an organic cause. Colonic inertia involves delayed passage of stool through the colon without abnormalities in the defecation process, resulting in constipation. Intestinal pseudo-obstruction is characterized by severe colonic dilation without an anatomic blockage.^[6][7]

Other lower tract disorders include pelvic floor dyssynergia, a functional obstruction from impaired relaxation of the puborectalis muscle or external anal sphincter that makes it difficult to evacuate stool. Hirschsprung’s disease, also known as congenital aganglionic megacolon, occurs when a section of the colon missing ganglion cells fails to relax, causing a functional obstruction.^[6]

Causes of Motility Disorders

The causes of intestinal motility disorders appear to be multifactorial, and only a few have been clearly identified. These disorders can result from damage to nerves, muscle, or both components of the enteric nervous system.^[6][14]

Studies on achalasia suggest it is primarily an autoimmune disorder. Worldwide, the most common cause of secondary achalasia is infection with Trypanosoma cruzi, which causes Chagas disease. Surgical errors during procedures like fundoplication or gastric banding can also cause achalasia. Systemic diseases that infiltrate the lower esophageal sphincter, such as tumors of the gastroesophageal junction or amyloidosis, can cause a condition similar to achalasia.^[6]

For gastroparesis, most cases are related to nerve damage from diabetes, complications following major stomach surgery, or occur for unknown reasons, referred to as idiopathic causes. The damage typically affects the nerves or muscles of the gut, leading to poor stomach emptying.^[8][14]

Very often, motility problems may be due to side effects from medications. For example, the antibiotic erythromycin can stimulate gut motility and cause diarrhea, while narcotics suppress gut motility and lead to constipation. Opioid medications are another common cause of motility dysfunction.^[4][14]

Risk Factors

Several factors can increase the risk of developing gastrointestinal motility disorders. Certain medical conditions predispose individuals to these problems, including diabetes, thyroid disease, neurological conditions like Parkinson’s disease, and autoimmune disorders.^[4][26]

Genetic factors also play a role in some motility disorders. Environmental exposures and the use of certain medications, particularly opioids, can significantly increase risk. For some conditions like Hirschsprung’s disease, there may be a rare inherited form.^[4][6]

Symptoms

The symptoms of gastrointestinal motility disorders vary depending on which part of the digestive system is affected. Upper intestinal motility disorders may present with difficulty or pain when swallowing, heartburn and acid reflux, a feeling of early fullness when eating, nausea, vomiting or regurgitation of food, burping, and weight loss. Some people may also experience abdominal distension and severe abdominal colicky pain.^[2][4][6]

Lower intestinal motility disorders commonly cause symptoms such as bloating, nausea, abdominal discomfort or pain, changes in bowel habits including chronic constipation or diarrhea, excessive gas, and in some cases, stool incontinence. These symptoms can also include recurrent obstruction and weight loss.^[4][6][7]

The impact of these symptoms on daily life can be significant. Bloating and pain can make it challenging to engage in physical activities or maintain a regular work schedule. The unpredictable nature of symptoms like diarrhea or the discomfort from constipation can affect social interactions and quality of life.^[2]

Prevention

While many motility disorders cannot be prevented due to their complex and often unknown causes, certain measures may help reduce risk or manage symptoms. Avoiding medications that can cause intestinal motility disorders, when possible, may help prevent these conditions or allow them to resolve.^[9][21]

Maintaining good overall health through proper management of conditions like diabetes and thyroid disease may help reduce the risk of developing motility problems. Since these chronic conditions can lead to nerve damage that affects gut function, keeping them well-controlled is important.^[4]

Lifestyle modifications and dietary changes can play a role in managing existing motility disorders and may help prevent symptom flare-ups. Working with healthcare providers to identify and avoid triggers specific to individual conditions can be beneficial.^[11]

Pathophysiology: How Motility Disorders Affect the Body

Under normal circumstances, food moves through the digestive system in a highly coordinated manner. The process begins in the esophagus, where muscular contractions transport food from the mouth to the stomach. In the stomach, food is mixed with digestive enzymes and acid to break it down into a semi-solid state. The partially digested food then moves into the small intestine, where most digestion and nutrient absorption occurs. Finally, it reaches the colon, where water and electrolytes are absorbed, transforming undigested food into feces.^[7][14]

Motility disorders significantly disrupt this normal functioning. These conditions cause the process of moving food through the digestive tract to either slow down or speed up. For example, gastroparesis results in delayed gastric emptying, which slows the movement of food from the stomach to the small intestine. This can lead to food remaining in the stomach too long, causing nausea, vomiting, and feelings of excessive fullness. On the other hand, conditions like some forms of irritable bowel syndrome can accelerate the transit process, leading to diarrhea.^[7][8]

The enteric nervous system controls motility, secretion, and sensation within the gut. Sensations from the gut are typically not perceived most of the time unless pain receptors are stimulated. These receptors are usually activated by stretching of the gut wall, called distension, or by cramping or inflammation. Usually, when the triggering event subsides, the pain goes away as well. However, in certain cases, silent pain receptors called nociceptors are activated and do not turn off after the initial problem has resolved, leaving the patient with chronic pain. This concept underlies many disorders of hypersensitivity, such as post-infectious irritable bowel syndrome.^[8][14]

These disorders can compromise the body’s ability to absorb nutrients effectively, leading to nutritional deficiencies. The impact on nutrition and daily activities makes dietary modifications and nutrition management critical for individuals with gastrointestinal motility disorders. The focus is often on foods that are easier to digest and nutrient-packed to compensate for malabsorption.^[7]