What is gastroparesis?
Most published literature describes gastroparesis as delayed gastric emptying without a mechanical obstruction.
At Children’s Hospital of Philadelphia (CHOP), our definition of gastroparesis is stricter. We consider gastroparesis to be a gastrointestinal (GI) motility disorder when there is objective delay in gastric emptying in the absence of any of the following:
- Mechanical obstruction
- Biochemical disorder (electrolyte imbalance, diabetes, hypothyroidism)
- Gastric infection (e.g. H. pylori gastritis, cytomegalovirus [CMV] gastritis, bacterial overgrowth)
- Medication side effect
- Significant non-infectious gastroduodenal inflammation (e.g. eosinophilic gastroenteritis, lymphocytic gastritis, celiac disease, Crohn’s disease, vasculitis)
Causes of gastroparesis
The term gastroparesis is ambiguous because it implies a specific condition — paralysis of the stomach — without addressing causes or severity.
The exact cause of gastroparesis is unknown. The stomach is not paralyzed. Instead, gastroparesis seems to be both a muscle and sensory problem (neuromuscular disorder).
Factors that may contribute to gastrointestinal symptoms include: antral hypomotility, gastric dysrhythmia, impaired gastric fundic accommodation, antral distention, visceral hypersensitivity and psychological disturbance.
Signs and symptoms of gastroparesis
Symptoms of gastroparesis mirror some symptoms of delayed gastric emptying and include:
- Early satiety (feeling full after only a few bites of food, inability to finish meals)
- Abdominal bloating (upper abdomen feels or actually looks distended, tight after eating)
- Abdominal pain or “burning” between the lower part of the breastbone and the navel
- Nausea (urge to vomit, queasy, “sick to stomach” sensation)
- Indigestion (combination of “burning,” feeling bloated, queasy after eating)
- Episodic vomiting
- Fear of eating
- Feeding difficulty in infants and young children
- Weight loss
These symptoms, however, are non-specific and do not distinguish gastroparesis from a mechanical, infectious or non-infectious inflammatory or biochemical disorder that also causes delayed gastric emptying.
To make diagnosing GI disorders even more challenging, these same symptoms may also occur in patients with normal gastric emptying, the degree of delay in gastric emptying does not predict symptom severity, and correlation between symptom reductions and improved emptying cannot be always demonstrated.
Often a companion diagnosis
In children, gastroparesis may be an acute primary self-limiting disorder triggered by infection, surgery or excessive weight loss. More commonly, however, pediatric gastroparesis overlaps in an individual patient with other chronic GI motility disorders including:
- Gastroesophageal reflux disease
- Functional dyspepsia
- Irritable bowel syndrome
- Cyclical vomiting
- Enteric dysmotility
Testing and diagnosis of gastroparesis
At Children's Hospital of Philadelphia, we offer expert clinicians and a full spectrum of diagnostic tests for gastrointestinal motility disorders at the Suzi and Scott Lustgarten Center for GI Motility. The Lustgarten Center provides diagnostic resources and integrated patient-centered services that are not available at most children's hospitals.
First, exclude what’s not gastroparesis
Before a definitive diagnosis of gastroparesis can be reached, physicians must rule out the possibility that other mechanical, infectious or non-infectious inflammatory and biochemical reasons are causing the delayed gastric emptying.
At the Lustgarten Center, our clinicians gather a comprehensive family history, perform a physical exam and schedule diagnostic tests for each pediatric patient with a suspected gastroparesis diagnosis. Diagnostic tests include: a barium contrast upper GI series, upper endoscopy, biochemical testing and a gastric emptying study.
Barium contrast upper GI series
In a barium contrast upper GI series, your child drinks a barium liquid that coats the upper GI tract, illuminating the flow of the liquid through the esophagus, stomach and duodenum. Completed under the careful supervision of a radiologist, this test rules out mechanical causes of delayed gastric emptying including gastric outlet obstruction, malrotation and partial small bowel obstruction.
An upper endoscopy allows your child's doctor to use an endoscope (a long, thin tube) to look at the lining of your child's stomach and proximal small bowel to confirm the absence of mechanical obstruction, and exclude infectious and inflammatory causes of delayed gastric emptying. This test can rule out H. Pylori gastritis, peptic ulcer, reactive gastritis, eosinophilic gastroenteritis, celiac disease and upper GI Crohn’s disease.
At CHOP, clinicians use a variety of biochemical tests to rule out correctable electrolyte and balance status, renal function and endocrine status.
Gastric emptying study
The “gold standard” for diagnosing gastroparesis is a gastric emptying study, a diagnostic test that measures the rate your child empties a standard radio-labeled solid meal over a defined period of time. In infants and small children, milk is used as the test meal.
At the Lustgarten Center, expert radiologists perform gastric emptying to evaluate patients. After radio-labeling the solid or liquid component of a meal, the gastric counts measured correlate directly with the volume of test meal remaining in the stomach.
Unfortunately, at this time, there is lack of national standardization of test protocol for pediatric patients. Techniques vary in hospitals regarding size or volume of the test meal used, patient positioning, frequency and duration of monitoring.
Additionally, there are differences between hospitals about how the quantitative data is reported. Hospitals may measure any of the following:
- Time to half-empty gastric contents
- Rate of gastric emptying (percentage per minute)
- Percent of gastric emptying at different time intervals (e.g. 30 minutes, 1 hour)
- Percent of gastric retention at different time intervals (e.g. 30 minutes, 1 hour)
In pediatrics, normal values have not been established for the protocols used. A standard practice at many hospitals has been to use adult normal values or to develop institutional norms developed from sub-populations of the patients studied.
A child undergoing a study will eat a radio-labeled egg (equivalent to two large eggs), bread or toast, and water as the solid test meal. Then, clinicians will measure the child’s percentage of gastric emptying at 30, 60, 90, and 120 minutes after the meal. Measurement is done with a gamma camera placed on the child's chest and abdomen to picture the perfused organs.
Patients are categorized as having delayed gastric emptying if emptying of the meal is less than 10 percent at 60 minutes or less than 50 percent at two hours post meal. These criteria are less strict than adult consensus guidelines established by the American Motility and Nuclear Medicine Society where two-hour emptying is considered delayed if less than 40 percent of the meal empties at 120 minutes.
Although adult studies have shown that extending measurements out to four hours increases the detection rate of delayed emptying in patients who appear normal at two hours, we feel our less stringent criteria at two hours will pick up this subgroup, and thus, reserve four-hour studies for patients with late postprandial symptoms.
Factors that must be considered in interpretation of test results include:
- Time to ingest the test meal.
- Presence of vomiting during the test, which can lead to values suggesting more rapid emptying.
- Medications the patient may be taking. (When medically possible, we ask patients to stop taking opiates, anti-cholinergic agents and prokinetic agents 48-72 hours before testing. Ondansetron [Zofran®] may be given before testing as it does not affect emptying and may help reduce nausea and chance for vomiting during the study.)
- The presence of significant hyperglycemia. (Ideally, the child’s blood glucose level should be lower than 275 mg/dl on the morning of the test if the patient has diabetes).
Since population studies have shown a poor correlation between a rate of solid gastric emptying and the severity of gastric symptoms, we use the scintigraphy test to classify patients as having objective evidence of delayed gastric emptying.
An antroduodenal manometry provides information about the muscle and nerve activity of the stomach and small bowel. The test can measure how strong and how well your child’s muscle contractions coordinate between the two organs. This test uses a catheter that has pressure sensors to record the contractions of the GI tract. The catheter contains pressure sensors that will measure stomach and intestinal contractions over approximately six hours during a fasting state and during a fed meal state.
A diagnosis of gastroparesis is established if upper GI series and endoscopy of the stomach and duodenum are normal, and biochemical testing rules out correctable electrolyte or metabolic disorder.
Treatment for gastroparesis
Gastroparesis is a very challenging disorder for pediatric gastroenterologists to treat. At present there is no standardized medical therapy for gastroparesis. Therapy must be individualized, and include dietary management, pharmacologic therapy and non-pharmacologic therapy.
At CHOP, therapy generally follows a step-up symptom-based protocol that is related to symptom severity and degree of disability, not to the degree of abnormal emptying. Our clinicians provide a multidisciplinary, patient-centered approach to care. We will coordinate with your child's primary care physician and other specialists to ensure the best management of the disease, and provide long-term follow-up care for your child.
Our ultimate goal is to help your child live as healthy, active and comfortable a life as possible.
Nutritional management of gastroparesis
Nutritional management of gastroparesis is based on the understanding of normal stomach emptying. Treatment approaches will vary based upon the severity of the disease and the patient’s nutritional status.
The goals of nutritional management are to ensure adequate calories, and that nutrients are consumed to promote your child’s growth and development. Maintaining a healthy diet can help control the symptoms of gastroparesis.
Dietary changes are tailored to each patient and may include:
- Eating small, frequent meals to allow the stomach to empty faster and reduce distention or bloating.
- Avoiding high fat foods, which tend to empty more slowly than carbohydrates or proteins.
- Reducing high fiber foods, such as raw vegetables, legumes or fruits.
- Drinking plenty of fluids during the meal and walking or sitting upright after meals can help speed stomach emptying.
- Implementing a FODMAP diet (low Fermentable Oligosaccharides, Disaccharide, Monosaccharides and Polyols) may be indicated in children who have severe symptoms of abdominal bloating or nausea. These carbohydrates are found in some of the foods that we eat and with the help of a registered dietitian, a modified diet can be achieved.
- For children who cannot eat enough to support growth, a nutritional supplement (such as PediaSure® or Boost®) and/or a multiple vitamin and mineral preparation may be added to ensure adequate nutrition.
Gastrostomy and jejunostomy
For children with severe nausea, vomiting and significant weight loss, placement of a nasogastric, nasojejunal or gastrostomy or jejunal tube may become necessary to ensure adequate hydration and adequate daily caloric intake.
A venting gastrostomy may reduce nausea and vomiting allowing the patient to increase daily oral caloric intake.
Rarely, patients with severe nausea, vomiting and weight loss may be unable to tolerate nutrients in gastric and small bowel feedings. These patients require central intravenous hyperalimentation.
Pharmacological therapies for gastroparesis
Although there is no cure for gastroparesis, the focus of pharmacological therapy is to improve patient lifestyle by attempting to improve gastric emptying, and targeting symptoms such as nausea, vomiting, abdominal bloating and abdominal pain.
A combination of medications is often used in individual patients. Each medication affects patients differently and a combination that may benefit one individual may not benefit another.
Medications that may enhance gastric emptying
- Erythromycin is a macrolide antibiotic that acts on the motilin receptor in nerve and smooth muscle to produce strong contractions in the gastric antrum and small intestine. Doses are lower than those used when the medication is being used is an antibiotic.
- Metoclopramide has multiple mechanisms including dopamine receptor antagonist, serotonin 5HT3 antagonist, serotonin 5HT4 agonist and modest anticholinesterase activity. The medication has a high side effect profile that includes fatigue, sleepiness, and depression — which are reversible by stopping the medication. A rare side effect called tardive dyskinesia is associated with impaired movement of fingers, lip smacking, rapid eye movements, blinking and tongue protrusion, which, in rare patients, may not be reversed by stopping the medication.
- Domperidone is a dopamine antagonist that can be used to treat serious gastrointestinal motility disorders in patients 12 years and older. Unlike metoclopramide, domperidone does not cross the blood-brain barrier. Thus, central nervous system side effects are rare. Domperidone increases plasma prolactin levels, which may rarely result in breast tenderness and galactorrhea. Domperidone can cause increased risk for cardiac arrhythmias. Authorization by the U.S. Food and Drug Administration to administer domperidone as a regulated drug to humans requires close cardiac monitoring and frequent visits with your gastroenterologist.
- Botulinum toxin (Botox®) has been associated with improvement in symptoms of gastroparesis in some patients. Botox is injected into pyloric muscle through an endoscope.
- Cisapride is a gastrointestinal, prokinetic agent that increases motility in the gastrointestinal tract by increasing the excitability of the esophagus, small intestine and colon. In comparison, metoclopramide acts only on the small intestine. Cisapride is regulated by the FDA and is only available at select highly specialized institutions. A risk of cisapride is serious cardiac arrhythmias, and for this reason the medication can only be prescribed and dispensed by participating providers to ensure careful monitoring. Patients must meet very strict eligibility criteria and be willing to follow the treatment schedule in order to participate.
All of the above therapies currently have variable results which can range from minimal to modest effects on gastric emptying, which suggests that their effect on symptoms of gastroparesis may be mediated by a different mechanism.
Medications that may reduce nausea and vomiting
- Selective serotonin 5HT3 antagonists, including ondansetron and granisetron
- Phenothiazines, most commonly prochlorperazine (Compazine®)
- Antihistamines, including meclizine and diphenhydramine which are antagonists of the histamine H1 receptor
- Cyproheptadine (Periactin™), a unique antihistamine that also has antimuscarinic, serotonin antagonist, and calcium channel blocking properties
- Scopolamine patch, an antimuscarinic agent
Medications that may reduce abdominal pain
- Tricyclic antidepressants (amitriptyline, nortriptyline), which reduce visceral hypersensitivity
- Gastric acid reduction therapy, such as proton pump inhibitors including omeprazole, lansoprazole, esomeprazole, pantoprazole, which are particularly helpful in patients that have overlapping symptoms of dyspepsia and gastroesophageal reflux disease
Medications that may reduce abdominal bloating
- Antifoaming/surfactants, including simethicone and activated charcoal, which alter the elasticity of gas bubbles and ease of passage of gas from the stomach
- Rifaximin, an antibiotic that lacks intestinal absorption and is highly active against aerobic and anaerobic bacteria which may overpopulate the stomach
- Flagyl — an antibiotic frequently used to treat bacterial overgrowth
Non-pharmacological therapies for gastroparesis
At CHOP's Lustgarten Center for GI Motility, children and their families also benefit from the support of child psychologists who work with the Hospital's GI motility patients to help them better manage their symptoms.
Psychological therapies such as stress management, cognitive behavioral therapy, relaxation therapy and biofeedback give children other ways to minimize the negative impacts of their disease on their quality of life. The involvement of a child psychologist is an integral part of the treatment plan.
In addition, our social workers can assist your child with school accommodations, including 504 planning.
In general, the overall goal of gastroparesis treatment is to help the patient achieve a healthier lifestyle by using a combination of nutritional, pharmacological and non-pharmacological therapies.
Outlook for gastroparesis
If your child with gastroparesis is successfully diagnosed and treated, your child can lead a relatively normal life. Though children with gastroparesis will need some lifestyle modification and to be medically followed into adulthood, they can attend school, get jobs and have families.