GI Testing in Kids
This is written from the perspective of an SLP/feeding specialist, and should not replace the advice of a physician, PA, or NP.
Fact – most tests in GI management are used to rule out something out rather than identify something.
I heard a gastroenterologist say this a few years back and it has helped me understand why some of our patients with significant feeding issues come out “within normal limits” on all of their testing. This can be very frustrating to caregivers who want to know what is wrong and why their child won’t eat. The reason for this may be partly due to the fact that many feeding issues that have corresponding GI problems are considered functional disorders and may not be captured on some of the tests. Many test involve eating and drinking and the child may not cooperate fully also skewing results.
For example, the child with reflux who goes for an Upper GI series or barium test in radiology. The child must lay on a table, drink barium, and then will be filmed until the barium moves from mouth to small intestine. That child may or may not have documented reflux on the test.The child will have to “reflux on cue” as my colleague once said meaning when the camera is on. The test is mainly used to rule out a structural reason for reflux such as mal-rotation of the intestine, hernia, fistula, etc. We have seen children have a completely normal test, declared to have “no reflux” by the radiologist and then vomit in the hall as they are leaving. Does that mean the child does not have reflux? Certainly not. It does mean that the child has normal anatomy which is very important information to have for some children because it may change the treatment.
This idea that tests are used to rule out certain diagnoses more than identify them is also why many doctors and GI Nurse practitioners start treatment with medical and nutritional management first before ordering tests. These decisions are always made on a case by case basis based on the child’s presenting symptoms and concerns. Testing may be used later if there is no improvement with medical management or earlier if there warning signs that warrant further study.
Here are some examples of the tests we use and what we are ruling out with information from the NASPAGHAN and ESPGHAN (North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) position paper.
Upper GI – X-ray (fluoroscopy test or moving x-ray) test used to assess structure and function of the upper digestive tract. Used to identify and rule out structural abnormalities such as mal-rotation of the bowel, stricture, fistula, and hernia. Can also sometimes see reflux, aspiration , and slower motility through digestive tract. This test is about 50% sensitive for reflux so if a child does not reflux on the test it does not mean the child does not have reflux.
- From NASPAGHAN/ESPGHAN paper: “This test is not useful for the diagnosis of GERD but is useful to confirm or rule out anatomic abnormalities of the upper gastrointestinal (GI) tract that may cause symptoms similar to those of GERD”.
Endoscopy – procedure used to rule out esophageal, stomach and small intestine issues including reflux esophagitis but more importantly eosinophillic esophagitis.
- From NASPAGHAN/ESPGHAN paper: Endoscopy and Biopsy Endoscopically are the most reliable evidence of reflux esophagitis. Conversely, absence of these histologic changes does not rule out GERD. Endoscopic biopsy is important to identify or rule out other causes of esophagitis, and to diagnose and monitor Barrett esophagus (BE) and its complications.
Gastric Emptying Study-nuclear radiology study used to rule out gastroparesis or slow gastric emptying.
- From NASPAGHAN/ESPGHAN paper: Gastric emptying studies are recommended only in individuals with symptoms of gastric retention.
PH probe or impedance testing – test used to assess for esophageal acidic reflux including frequency and severity. May be used to rule out severity of acidic reflux (and nonacidic reflux on impedance) but results can be unclear. Generally used for more severe reflux.
- From NASPAGHAN: Esophageal pH may be useful for evaluating the effect of antacid medicines, to correlate symptoms (eg, cough, chest pain) with reflux episodes, and to those with wheezing or respiratory symptoms in whom GER is an aggravating factor. The sensitivity, specificity, and clinical utility of pH monitoring are not well established. Whether combined esophageal pH and impedance monitoring will provide useful measurements that vary directly with disease severity, prognosis, and response to therapy in pediatric patients has yet to be determined.
Manometry testing – specialized test used to rule out motility disorders in various parts of the digestive tract.
- From NASPAGHAN/ESPGHAN paper: may be useful to diagnose a motility disorder in patients who have failed acid suppression and who have a normal endoscopy. Manometric studies are useful to confirm a diagnosis of achalasia or other motor disorders of the esophagus that may mimic GERD.
Final thoughts on GI testing: Most children with GI issues and feeding difficulty will start treatment with medical and/or nutritional management based on the child’s feeding problems and presenting symptoms before tests are ordered unless there is a strong reason to test first (this is case by case). Management can include trials of different types of medicine and formulas to figure out what the child will respond to best. While we don’t have specific data, many children improve with these types of interventions even before testing is ordered. The doctor/nurse practitioner will order medical tests as needed to help guide the child’s intervention. Probably the most common test to begin with is the UGI because if a child presents with vomiting, the physician may want to rule out a structural issue before proceeding with medical management.
It is important to reassure caregivers that a normal result on a test does not mean that their child is not having feeding issues. It just means certain types of contributing problems are being ruled out to help guide the child’s intervention.
Reference: Pediatric Gastroesophageal Reflux Clinical Practice Guidelines:
Joint Recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN). Co-Chairs: Yvan Vandenplas and Colin D. Rudolph
Committee Members: Carlo Di Lorenzo, Eric Hassall, jGregory Liptak, Lynnette Mazur, Judith Sondheimer, Annamaria Staiano, Michael Thomson, Gigi Veereman-Wauters, and Tobias G. Wenzl
Journal of Pediatric Gastroenterology and Nutrition. 49:498–547 # 2009 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition