Motility Center

Gastrointestinal motility is defined as the neuromuscular activity of the gastrointestinal tract. This process involves muscles, nerves and hormones. The physicians at Specialists of Gastroenterology help patients who have problems in this area. We are involved in the diagnosis and treatment of all gastrointestinal motility disorders including:

Motility Image

Normal motility and digestion

When you eat the esophagus creates peristaltic waves to move the food down and then the lower esophageal sphincter relaxes to allow the food to go into the stomach. The upper esophageal muscle also relaxes during the swallowing process of food or saliva, and then stays shut the rest of the time in order to prevent food going up into the mouth or airways. When you are fasting or finish swallowing, the circular sphincter muscle stays tightly closed to prevent stomach contents from coming back up into the esophagus.

As food enters the stomach there is initial relaxation to allow the food to fill up the stomach. The pyloric sphincter stays closed to aid the process of digestion. Stomach motility allows the food to mix with its juices (acid, pepsin, intrinsic factor). The food breaks down into small particles which then pass into the small intestine (duodenum, jejunum, and ileum). The small intestine is responsible for absorbing the nutrients and water. It also secretes water and electrolytes to aid in the process of digestion. The digestive hormone CCK is responsible for coordinating contraction of the gallbladder and relaxation of the sphincter of Oddi; this process allows passage of bile into the small intestine to help absorb fat. The ileocecal valve sphincter stays shut to act as the "ileal brake", this prevents food passing through the intestine too quickly. The unbound bile and vitamin B12 attached to intrinsic factor are absorbed in the ileum.

Finally, fluids, digested food, and undigested food material pass into the large intestine. The coordination of the activity of trillions of colon bacteria, normal colonic lining function, colon motility, sphincter activity (ileocecal valve, internal and external anal sphincters), and the puborectalis muscle sling are responsible for the last steps in digestion. Thus, the process of turning the small intestinal fluid into a well formed bowel movement is a complicated series of events.

Esophageal motility disorders

Acid reflux is the most common problem. Over 10% of Americans have experienced heartburn owing to reflux of acid back into the esophagus.

Dysphagia or difficulty swallowing is a common problem, which can be structural or neuromuscular in origin. Esophageal manometry, endoscopy and barium studies are the basic tools to diagnose and/or lead the way toward treatment.

Stomach motility disorders

Motility SmartPillUsually these conditions are slow activity problems but rarely can be too quick. The motility of the stomach is commonly measured with the nuclear gastric emptying test, where you eat a meal mixed with a tracer and then images are obtained at 1, 2, and 4 hours. At SIG we also have the SmartPill which is a unique diagnostic test.

Biliary tract motility disorders

The most common biliary tract motility disorders include: 1) Gallbladder dyskinesia – this is often due to scarring of the cystic duct which results in decreased gallbladder ejection fraction, and 2) Sphincter of Oddi dysfunction – this can occur secondary to stenosis, scarring, and/or spasm of the sphincter.

Intestinal motility disorders

This describes a variety of disorders in which the intestines have the lost ability to coordinate the muscular activity necessary for normal transit. This may result from damage/dysfunction of the muscles (myopathic) and/or the nerves (neuropathic). Some of the conditions which can alter intestinal motility include: irritable bowel syndrome, intestinal pseudo-obstruction, brain-gut dysfunction, hypothyroidism, postsurgical changes, medication induced (opiates), radiation, diabetic neuropathy, rheumatologic conditions such as scleroderma, and Ehlers-Danlos syndrome.

Small intestine motility disorders may be evaluated with the SmartPill; this capsule collects pressure, pH, and temperature data from your GI tract, and wirelessly transmits that information to a data receiver worn on a belt or a lanyard. These physiological measurements are then used to determine gastric emptying time, whole gut transit time, and combined small-large bowel transit time.

Colonic motility disorders

This describes disorders which affect the activity of the large intestine, which may be muscular (myopathic) or neural (neuropathic) in origin. Some of the conditions which can alter the motility of the colon include: irritable bowel syndrome, colonic pseudo-obstruction, slow-transit constipation, brain-gut dysfunction, medication induced (opiates, anticholinergics, iron supplements), radiation, hypercalcemia, hyperparathyroidism, hypothyroidism, and scleroderma.

Pelvic floor and anal sphincter motility disorders

One of the most common causes of anorectal motility dysfunction is pelvic floor dyssynergia. This describes a condition in which the pelvic floor muscles (the puborectalis) and the anal sphincter muscles fail to relax, or paradoxically contract, during attempted defecation. Inadequate defecatory propulsion can also play a role, this occurs due to insufficient increase in rectal or intra-abdominal pressure during defecation. Abnormal rectal anal inhibitory reflex (RAIR), as seen in Hirschsprung's and Chagas disease, is also implicated. Finally, anatomic abnormalities that may lead to obstructive defecation include rectoceles, sigmoidoceles, enteroceles, prolapse, and intussusception.

Pelvic floor dysfunction may be diagnosed with anorectal manometry and/or the balloon expulsion test.

Anywhere along the way, people can develop problems including bloating, gas, diarrhea, constipation, and evacuation or pelvic floor disorders.