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Allen Lee, MD
Department of Medicine
Division of Gastroenterology and Hepatology
University of Michigan
Ann Arbor, Michigan
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William Hasler, MD
Department of Medicine
Division of Gastroenterology and Hepatology
University of Michigan
Ann Arbor, Michigan
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Jason Baker, BS, MS
Deputy Director, GI Physiology Laboratory
Michigan Bowel Control Program
Department of Medicine
University of Michigan
Ann Arbor, Michigan

Functional gastrointestinal disorders (FGIDs) are common, and diagnosed by specific symptom complexes. FGIDs are defined by Rome IV criteria in the absence of anatomic or organic causes.1 Questionnaire studies suggest that up to 69% of respondents reported symptoms of at least 1 FGID in the past 3 months.2 Furthermore, FGIDs often overlap with other conditions with the majority of patients showing overlap between 2 or more functional disorders.3 Moreover, symptom complexes may not be stable; about 50% of patients change symptoms over a 1-year period.4

In contrast, GI motility disorders are defined by objective motility abnormalities based on specific tests. Motility tests provide valuable information by identifying individuals with defined motility abnormalities (eg, gastroparesis, small bowel dysmotility, and slow transit constipation), differentiating between FGIDs and motility disorders, guiding target therapeutic choices based on specific motility abnormalities, and providing important prognostic information before surgery.5

Case Presentation

A 29-year-old woman presents with 15 months of progressively worsening nausea and vomiting. Symptoms were aggravated by meals and associated with early satiation, bloating, and visible abdominal distention, as well as alternating diarrhea and constipation. Previous workup including laboratory tests, upper endoscopy, colonoscopy, CT scan, and ultrasound were remarkable only for retained food in the stomach suggestive of gastroparesis. Treatment with metoclopramide and domperidone either caused intolerable side effects or failed to provide symptom relief.

She was subsequently referred to our institution for refractory gastroparesis. Repeat EGD and colonoscopy with random biopsies of the duodenum, terminal ileum, and colon were normal. A 4-hour gastric emptying scintigraphy test also was normal. Small bowel follow-through showed relatively rapid transit time but was otherwise normal. Trials of various antiemetic agents, antisecretory agents, laxatives, and antispasmodics were ineffective. The patient ultimately underwent testing using a wireless motility capsule (WMC), which demonstrated a gastric emptying time of 10 hours and 32 minutes (normal, ≤5 hours), a small bowel transit time of 13 hours and 21 minutes (normal, 2.5-6 hours), and a colon transit time of 94 hours and 16 minutes (normal, 5-59 hours) (Figure). The patient was subsequently started on dronabinol 5 mg twice daily and linaclotide 145 mcg daily to address the generalized delay suspected of being a major source of her symptoms. Her symptoms have improved considerably with less nausea and bloating, and more regular bowel habits.

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Figure. Wireless motility tracing from case study patient.
Gastric emptying time was delayed at 10 h 32 min (shown by abrupt rise in pH; normal, <5 h). The capsule exited the small bowel at 23 h 53 min (shown by sustained pH drop), yielding a prolonged small bowel transit time of 13 h 21 min (normal, 2.5-6 h). The capsule exited the body at 118 h 9 min (shown by abrupt drop in temperature), yielding a prolonged colonic transit time of 94 h 16 min

Discussion

Differentiating between FGIDs and motility disorders can be difficult because symptoms often correlate poorly with physiologic tests. The WMC is a nonradioactive, ambulatory test that continuously records pH, pressure, and temperature for up to 5 days after ingestion as the capsule moves through the GI tract. Thus, the WMC can simultaneously measure pressure profiles and transit both regionally and throughout the entire gut. Industry-sponsored, multicenter trials have compared and validated the WMC with gastric emptying scintigraphy for the measurement of gastric emptying and with radiopaque marker studies for the measurement of colonic transit times; these studies have demonstrated very good correlation with overall correlation coefficients of 0.73 and 0.78, respectively.6,7 In addition, sensitivity for detection of gastroparesis is likely higher for the WMC than gastric emptying scintigraphy.6 Of subjects with suspected gastroparesis, 65% demonstrated delay in gastric emptying time by WMC testing compared with 44% by gastric emptying scintigraphy.6

As in this case, WMC testing may be particularly helpful for individuals who present with symptoms suggestive of upper-gut (eg, nausea, vomiting, bloating, and fullness) and lower-gut dysmotility (eg, constipation, diarrhea, and lower abdominal pain). Kuo and colleagues published a retrospective study of 83 subjects with suspected gastroparesis, intestinal dysmotility, or slow transit constipation. Compared with conventional motility testing, the WMC provided a new diagnosis in 53% of cases and importantly, influenced management in two-thirds of the cases.5 This result suggests that WMC may be helpful in the diagnosis and management of individuals with FGIDs who present with a multitude of GI symptoms.

References

  1. Drossman DA, Hasler WL. Gastroenterology. 2016;150(6):1257-1261.
  2. Drossman DA, Li Z, Andruzzi E, et al. Dig Dis Sci. 1993;38(9):1569-1580.
  3. Locke GR, Zinsmeister AR, Fett SL, et al. Neurogastroenterol Motil. 2005;17(1):29-34.
  4. Agréus L, Svärdsudd K, Nyrén O, et al. Gastroenterology. 1995;109(3):671-680.
  5. Kuo B, Maneerattanaporn M, Lee AA, et al. Dig Dis Sci. 2011;56(10):2928-2938.
  6. Kuo B, McCallum RW, Koch KL, et al. Aliment Pharmacol Ther. 2008;27(2):186-196.
  7. Rao SS, Kuo B, McCallum RW, et al. Clin Gastroenterol Hepatol. 2009;7(5):537-544.