Helicobacter pylori Infection: Laboratory Support of Diagnosis and Management
Helicobacter pylori Infection: Laboratory Support of Diagnosis and Management
This Clinical Focus provides information on Helicobacter pylori infection, focusing on the selection and interpretation of laboratory tests for diagnosis and assessing treatment response.
Clinical Focus
Helicobacter pylori Infection
Laboratory Support of Diagnosis and Management
Individuals suitable for testing
- Table 1. Tests Available for Diagnosis and Management of H pylori Infection
- Table 2. Characteristics of Nonendoscopic Tests for H pylori
Clinical background [return to contents]
Helicobacter pylori infection is a common bacterial infection that causes chronic gastritis.1,2 The estimated prevalence of H pylori infection is 36% in the United States and >50% worldwide.3 Many people with H pylori infection are asymptomatic, but some develop serious gastrointestinal (GI) diseases including peptic ulcer disease, gastric cancer, and gastric mucosa–associated lymphoid tissue (MALT) lymphoma.4 Infection is usually acquired during childhood and is associated with low socioeconomic status, higher sibling number, and having a parent with H pylori infection.1,5
Diagnosis and treatment of H pylori infection are important because infection is rarely self-limiting.4 A variety of diagnostic tests can detect infection, including a stool antigen test, urea breath test (UBT), rapid urease test, histology, culture, serology, and others. Serology was previously the most common approach, but it is no longer recommended because of its lower sensitivity and specificity for active infection.6,7
Treatment of H pylori infection typically involves a 10 to 14-day multidrug regimen, followed by testing for eradication at least 4 weeks after the end of treatment.5 Testing for eradication is important because H pylori eradication rates are declining. Most studies of current first-line therapies in the United States report eradication rates ≤80%.2 Increasing rates of antibiotic resistance are largely responsible for the decline in treatment success, leading to greater interest in testing for antibiotic susceptibility to inform treatment selection.2,7
This Clinical Focus discusses how laboratory testing supports diagnosis and management of H pylori infection. The material is provided for informational purposes only and is not intended as medical advice. Test selection and interpretation, diagnosis, and patient management decisions should be based on the physician's education, clinical expertise, and assessment of the patient.
Individuals suitable for testing [return to contents]
Diagnostic testing
- Patients with active peptic ulcer disease, gastric intestinal metaplasia, atrophic gastritis, uninvestigated dyspepsia, low-grade MALT lymphoma, unexplained iron deficiency anemia, or idiopathic thrombocytopenic purpura5,6,8-10
- Patients with a history of uncured peptic ulcer disease or endoscopic resection of early gastric cancer5,6
- Patients using long-term, low-dose aspirin or initiating chronic treatment with a non-steroidal anti-inflammatory drug (NSAID)5
- Individuals who cohabitate with patients with active H pylori infections, have a family history of peptic ulcer disease or gastric cancer, or are members of high-risk groups (eg, first-generation immigrants from high-prevalence countries)6
Post-treatment testing
- Patients at ≥4 weeks after completing eradication therapy for H pylori infection5,11
Test availability [return to contents]
Laboratory tests for diagnosis and management of H pylori infection can be categorized as endoscopic or nonendoscopic.4 Endoscopic tests require GI tract biopsy specimens that are obtained during an invasive endoscopy, whereas nonendoscopic tests involve noninvasive specimen collection. Quest Diagnostics offers testing options for endoscopic and nonendoscopic specimens (Table 1). Additional information on available nonendoscopic tests is provided in Table 2.
Table 1. Tests Available for Diagnosis and Management of H pylori Infection
Test code |
Assay |
Method |
Clinical use |
||
Endoscopic biopsy specimens |
|||||
16597 |
Helicobacter pylori Culturea |
Culture |
Isolate organism for susceptibility testing |
||
36994 |
Helicobacter pylori, Culture With Reflex to Susceptibilitya,b |
Culture; antibiotic gradient diffusion |
Guide treatment selection |
||
36995 |
Susceptibility, Antimicrobial, Helicobacter pylori, MIC |
Antibiotic gradient diffusion |
Guide treatment selection |
||
Nonendoscopic specimens |
|||||
34838 |
Helicobacter pylori Antigen, EIA, Stool |
Enzyme immunoassay |
Diagnose current infection; assess treatment response; |
||
14839 |
Helicobacter pylori, Urea Breath Test |
Infrared spectrophotometry |
|||
92491 |
Helicobacter pylori, Urea Breath Test, Pediatric |
||||
| a | This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the US Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes. |
| b | Reflex tests are performed at an additional charge and are associated with an additional CPT code(s). |
Table 2. Characteristics of Nonendoscopic Tests for H pylori
|
Urea breath testing12 |
Stool antigen detection13 |
Test name (test code) |
≥18 years of age 3-17 years of age |
All ages |
Measures |
13CO2 release |
H pylori antigen |
Method |
Infrared spectrophotometry:
|
Enzyme immunoassay:
|
Primary reagent |
13C-urea |
H pylori antibodies coupled to horseradish peroxidase |
Reference range |
Not detected |
Not detected |
| Clinical sensitivityb, % (95% CI) | ||
Diagnosis |
100 (90%-100%) |
100 (89%-99%) |
Assess eradication |
Not reported |
78 (45%-94%) |
Clinical specificityb, % (95% CI) |
||
Diagnosis |
100 (97%-100%) |
96 (89%-99%) |
Assess eradication |
Not reported |
Not reported |
Causes of false positives |
Achlorhydria; other urease-producing organisms (eg, H heilmannii) |
None known |
Causes of false negatives |
Proton pump inhibitorsc |
Proton pump inhibitorsc |
|
Antimicrobialsc |
Antimicrobialsc |
|
Bismuth-containing compoundsc |
Bismuth-containing compoundsc |
|
|
Very low antigen levels |
Sample type |
1 bag of baseline breathd and 1 bag of post–13C-urea ingestion breath |
Minimum of 0.5 mL or 0.5 g of liquid/semi-solid stool or 20 mm diameter solid stool |
Sample stability |
||
Ambient |
1 week |
4 days |
Refrigerated |
Unacceptable |
4 days |
Frozen |
Unacceptable |
14 days |
| a | The performance characteristics of this test have not been established for individuals <3 years of age. |
| b | The performance characteristics of the stool antigen test have not been established for asymptomatic individuals. Colonic washes, barium enemas, laxatives, or bowel preparations can result in extensive dilution or the presence of additives that may affect test performance. |
| c | Ingestion of these medications ≤2 weeks before testing may cause a false negative result. If clinically indicated, the test may be repeated on a new specimen obtained 2 weeks after stopping treatment with these medications. |
| d | Patients should fast for ≥1 hour prior to baseline sample collection. |
Test selection and interpretation [return to contents]
Diagnostic testing
Tests performed on endoscopic biopsy specimens (eg, rapid urease test, histologic examination, or culture) and nonendoscopic tests (eg, UBT or the stool antigen test) can be used for the diagnosis of H pylori infection. Test selection depends on the clinical indication, test availability, and patient preferences.4,7 Nonendoscopic tests are often preferred because they do not require invasive procedures.7 Tests that require endoscopic biopsy specimens are typically performed for more severe disease indications, such as active peptic ulcer disease or suspected gastric cancer.4,7
For patients with uninvestigated dyspepsia, test selection also depends on age. For patients <60 years of age, a test-and-treat strategy is recommended where patients are first tested with a nonendoscopic assay (usually a stool antigen test or UBT) followed by treatment to eradicate H pylori, if indicated.9 Patients ≥60 years of age are recommended to receive an endoscopy to rule out upper GI neoplasia.9 Those with normal endoscopic findings and unknown H pylori infection status should have gastric biopsies obtained for H pylori testing.9,14
For all types of H pylori tests, positive results indicate H pylori infection. Guidelines indicate that all patients with positive results be offered H pylori eradication therapy.4-6,9,10 Therefore, diagnostic testing for H pylori should only be performed if the clinician plans to offer treatment to patients who receive positive results.4
Post-treatment testing
Treatment success should be assessed by follow-up testing with a nonendoscopic test, such as UBT or a stool antigen test, or a biopsy-based test if an endoscopy is indicated.4,5 Testing should be performed at least 4 weeks after completing eradication therapy.5,11 This approach allows any remaining H pylori to recover and repopulate the stomach in sufficient numbers to be detected reliably.15 Detection of H pylori following eradication therapy indicates recurrence or ineffective treatment.
Assessment of H pylori antimicrobial susceptibility can assist treatment selection after persistent infection. After 2 failed treatments with confirmed patient adherence, the American Gastroenterological Association advises consideration of H pylori susceptibility testing to guide selection of subsequent treatment regimens.11 Phenotypic susceptibility testing using agar dilution or antibiotic gradient diffusion requires culture of endoscopic biopsy specimens to isolate H pylori.1 Culture-based susceptibility testing offered by Quest assesses response to clarithromycin, amoxicillin, levofloxacin, metronidazole, and tetracycline.
References [return to contents]
- Azad KN, Realegeno SE, Kagan RM, et al. An easily digestible review of Helicobacter pylori diagnostics. Clin Microbiol Newsl. 2022;44(6):51-61. doi:10.1016/j.clinmicnews.2022.03.001
- Shah S, Hubscher E, Pelletier C, et al. Helicobacter pylori infection treatment in the United States: clinical consequences and costs of eradication treatment failure. Expert Rev Gastroenterol Hepatol. 2022;16(4):341-357. doi:10.1080/17474124.2022.2056015
- Hooi JKY, Lai WY, Ng WK, et al. Global prevalence of Helicobacter pylori infection: systematic review and meta-analysis. Gastroenterology. 2017;153(2):420-429. doi:10.1053/j.gastro.2017.04.022
- World Gastroenterology Organisation global guidelines: Helicobacter pylori. Updated May 2021. Accessed March 9, 2023. https://www.worldgastroenterology.org/guidelines/helicobacter-pylori/helicobacter-pylori-english
- Chey WD, Leontiadis GI, Howden CW, et al. ACG clinical guideline: treatment of Helicobacter pylori infection. Am J Gastroenterol. 2017;112(2):212-239. doi:10.1038/ajg.2016.563
- El-Serag HB, Kao JY, Kanwal F, et al. Houston Consensus Conference on testing for Helicobacter pylori infection in the United States. Clin Gastroenterol Hepatol. 2018;16(7):992-1002.e6. doi:10.1016/j.cgh.2018.03.013
- Lee YC, Dore MP, Graham DY. Diagnosis and treatment of Helicobacter pylori infection. Annu Rev Med. 2022;73:183-195. doi:10.1146/annurev-med-042220-020814
- Gupta S, Li D, El Serag HB, et al. AGA clinical practice guidelines on management of gastric intestinal metaplasia. Gastroenterology. 2020;158(3):693-702. doi:10.1053/j.gastro.2019.12.003
- Moayyedi P, Lacy BE, Andrews CN, et al. ACG and CAG clinical guideline: management of dyspepsia. Am J Gastroenterol. 2017;112(7):988-1013. doi:10.1038/ajg.2017.154
- Shah SC, Piazuelo MB, Kuipers EJ, et al. AGA clinical practice update on the diagnosis and management of atrophic gastritis: expert review. Gastroenterology. 2021;161(4):1325-1332.e7. doi:10.1053/j.gastro.2021.06.078
- Shah SC, Iyer PG, Moss SF. AGA clinical practice update on the management of refractory Helicobacter pylori infection: expert review. Gastroenterology. 2021;160(5):1831-1841. doi:10.1053/j.gastro.2020.11.059
- PyloPlus® UBT Kit for PyloPlus® UBT System. Package insert. Gulf Coast Scientific Inc; 2023. Accessed March 2, 2023. https://www.gulfcoastscientific.com/wp-content/uploads/2023/02/PPUBT-PACKAGE-INSERT-2-PAGE-FORMAT-REV_B_COMPLETE.pdf
- H. PYLORI CHEK™. Package insert. TECHLAB Inc; 2022. Accessed March 8, 2023. https://www.techlab.com/wp-content/uploads/2022/12/H-PYLORI-CHEK-PI-92-051-01-TL_12_2022-read.pdf
- Yang YX, Brill J, Krishnan P, et al. American Gastroenterological Association Institute guideline on the role of upper gastrointestinal biopsy to evaluate dyspepsia in the adult patient in the absence of visible mucosal lesions. Gastroenterology. 2015;149(4):1082-1087. doi:10.1053/j.gastro.2015.07.039
- Attumi TA, Graham DY. Follow-up testing after treatment of Helicobacter pylori infections: cautions, caveats, and recommendations. Clin Gastroenterol Hepatol. 2011;9(5):373-375. doi:10.1016/j.cgh.2010.12.025
Content reviewed 04/2023
This Clinical Focus provides information on Helicobacter pylori infection, focusing on the selection and interpretation of laboratory tests for diagnosis and assessing treatment response.
Clinical Focus
Helicobacter pylori Infection
Laboratory Support of Diagnosis and Management
Individuals suitable for testing
- Table 1. Tests Available for Diagnosis and Management of H pylori Infection
- Table 2. Characteristics of Nonendoscopic Tests for H pylori
Clinical background [return to contents]
Helicobacter pylori infection is a common bacterial infection that causes chronic gastritis.1,2 The estimated prevalence of H pylori infection is 36% in the United States and >50% worldwide.3 Many people with H pylori infection are asymptomatic, but some develop serious gastrointestinal (GI) diseases including peptic ulcer disease, gastric cancer, and gastric mucosa–associated lymphoid tissue (MALT) lymphoma.4 Infection is usually acquired during childhood and is associated with low socioeconomic status, higher sibling number, and having a parent with H pylori infection.1,5
Diagnosis and treatment of H pylori infection are important because infection is rarely self-limiting.4 A variety of diagnostic tests can detect infection, including a stool antigen test, urea breath test (UBT), rapid urease test, histology, culture, serology, and others. Serology was previously the most common approach, but it is no longer recommended because of its lower sensitivity and specificity for active infection.6,7
Treatment of H pylori infection typically involves a 10 to 14-day multidrug regimen, followed by testing for eradication at least 4 weeks after the end of treatment.5 Testing for eradication is important because H pylori eradication rates are declining. Most studies of current first-line therapies in the United States report eradication rates ≤80%.2 Increasing rates of antibiotic resistance are largely responsible for the decline in treatment success, leading to greater interest in testing for antibiotic susceptibility to inform treatment selection.2,7
This Clinical Focus discusses how laboratory testing supports diagnosis and management of H pylori infection. The material is provided for informational purposes only and is not intended as medical advice. Test selection and interpretation, diagnosis, and patient management decisions should be based on the physician's education, clinical expertise, and assessment of the patient.
Individuals suitable for testing [return to contents]
Diagnostic testing
- Patients with active peptic ulcer disease, gastric intestinal metaplasia, atrophic gastritis, uninvestigated dyspepsia, low-grade MALT lymphoma, unexplained iron deficiency anemia, or idiopathic thrombocytopenic purpura5,6,8-10
- Patients with a history of uncured peptic ulcer disease or endoscopic resection of early gastric cancer5,6
- Patients using long-term, low-dose aspirin or initiating chronic treatment with a non-steroidal anti-inflammatory drug (NSAID)5
- Individuals who cohabitate with patients with active H pylori infections, have a family history of peptic ulcer disease or gastric cancer, or are members of high-risk groups (eg, first-generation immigrants from high-prevalence countries)6
Post-treatment testing
- Patients at ≥4 weeks after completing eradication therapy for H pylori infection5,11
Test availability [return to contents]
Laboratory tests for diagnosis and management of H pylori infection can be categorized as endoscopic or nonendoscopic.4 Endoscopic tests require GI tract biopsy specimens that are obtained during an invasive endoscopy, whereas nonendoscopic tests involve noninvasive specimen collection. Quest Diagnostics offers testing options for endoscopic and nonendoscopic specimens (Table 1). Additional information on available nonendoscopic tests is provided in Table 2.
Table 1. Tests Available for Diagnosis and Management of H pylori Infection
Test code |
Assay |
Method |
Clinical use |
||
Endoscopic biopsy specimens |
|||||
16597 |
Helicobacter pylori Culturea |
Culture |
Isolate organism for susceptibility testing |
||
36994 |
Helicobacter pylori, Culture With Reflex to Susceptibilitya,b |
Culture; antibiotic gradient diffusion |
Guide treatment selection |
||
36995 |
Susceptibility, Antimicrobial, Helicobacter pylori, MIC |
Antibiotic gradient diffusion |
Guide treatment selection |
||
Nonendoscopic specimens |
|||||
34838 |
Helicobacter pylori Antigen, EIA, Stool |
Enzyme immunoassay |
Diagnose current infection; assess treatment response; |
||
14839 |
Helicobacter pylori, Urea Breath Test |
Infrared spectrophotometry |
|||
92491 |
Helicobacter pylori, Urea Breath Test, Pediatric |
||||
| a | This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the US Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes. |
| b | Reflex tests are performed at an additional charge and are associated with an additional CPT code(s). |
Table 2. Characteristics of Nonendoscopic Tests for H pylori
|
Urea breath testing12 |
Stool antigen detection13 |
Test name (test code) |
≥18 years of age 3-17 years of age |
All ages |
Measures |
13CO2 release |
H pylori antigen |
Method |
Infrared spectrophotometry:
|
Enzyme immunoassay:
|
Primary reagent |
13C-urea |
H pylori antibodies coupled to horseradish peroxidase |
Reference range |
Not detected |
Not detected |
| Clinical sensitivityb, % (95% CI) | ||
Diagnosis |
100 (90%-100%) |
100 (89%-99%) |
Assess eradication |
Not reported |
78 (45%-94%) |
Clinical specificityb, % (95% CI) |
||
Diagnosis |
100 (97%-100%) |
96 (89%-99%) |
Assess eradication |
Not reported |
Not reported |
Causes of false positives |
Achlorhydria; other urease-producing organisms (eg, H heilmannii) |
None known |
Causes of false negatives |
Proton pump inhibitorsc |
Proton pump inhibitorsc |
|
Antimicrobialsc |
Antimicrobialsc |
|
Bismuth-containing compoundsc |
Bismuth-containing compoundsc |
|
|
Very low antigen levels |
Sample type |
1 bag of baseline breathd and 1 bag of post–13C-urea ingestion breath |
Minimum of 0.5 mL or 0.5 g of liquid/semi-solid stool or 20 mm diameter solid stool |
Sample stability |
||
Ambient |
1 week |
4 days |
Refrigerated |
Unacceptable |
4 days |
Frozen |
Unacceptable |
14 days |
| a | The performance characteristics of this test have not been established for individuals <3 years of age. |
| b | The performance characteristics of the stool antigen test have not been established for asymptomatic individuals. Colonic washes, barium enemas, laxatives, or bowel preparations can result in extensive dilution or the presence of additives that may affect test performance. |
| c | Ingestion of these medications ≤2 weeks before testing may cause a false negative result. If clinically indicated, the test may be repeated on a new specimen obtained 2 weeks after stopping treatment with these medications. |
| d | Patients should fast for ≥1 hour prior to baseline sample collection. |
Test selection and interpretation [return to contents]
Diagnostic testing
Tests performed on endoscopic biopsy specimens (eg, rapid urease test, histologic examination, or culture) and nonendoscopic tests (eg, UBT or the stool antigen test) can be used for the diagnosis of H pylori infection. Test selection depends on the clinical indication, test availability, and patient preferences.4,7 Nonendoscopic tests are often preferred because they do not require invasive procedures.7 Tests that require endoscopic biopsy specimens are typically performed for more severe disease indications, such as active peptic ulcer disease or suspected gastric cancer.4,7
For patients with uninvestigated dyspepsia, test selection also depends on age. For patients <60 years of age, a test-and-treat strategy is recommended where patients are first tested with a nonendoscopic assay (usually a stool antigen test or UBT) followed by treatment to eradicate H pylori, if indicated.9 Patients ≥60 years of age are recommended to receive an endoscopy to rule out upper GI neoplasia.9 Those with normal endoscopic findings and unknown H pylori infection status should have gastric biopsies obtained for H pylori testing.9,14
For all types of H pylori tests, positive results indicate H pylori infection. Guidelines indicate that all patients with positive results be offered H pylori eradication therapy.4-6,9,10 Therefore, diagnostic testing for H pylori should only be performed if the clinician plans to offer treatment to patients who receive positive results.4
Post-treatment testing
Treatment success should be assessed by follow-up testing with a nonendoscopic test, such as UBT or a stool antigen test, or a biopsy-based test if an endoscopy is indicated.4,5 Testing should be performed at least 4 weeks after completing eradication therapy.5,11 This approach allows any remaining H pylori to recover and repopulate the stomach in sufficient numbers to be detected reliably.15 Detection of H pylori following eradication therapy indicates recurrence or ineffective treatment.
Assessment of H pylori antimicrobial susceptibility can assist treatment selection after persistent infection. After 2 failed treatments with confirmed patient adherence, the American Gastroenterological Association advises consideration of H pylori susceptibility testing to guide selection of subsequent treatment regimens.11 Phenotypic susceptibility testing using agar dilution or antibiotic gradient diffusion requires culture of endoscopic biopsy specimens to isolate H pylori.1 Culture-based susceptibility testing offered by Quest assesses response to clarithromycin, amoxicillin, levofloxacin, metronidazole, and tetracycline.
References [return to contents]
- Azad KN, Realegeno SE, Kagan RM, et al. An easily digestible review of Helicobacter pylori diagnostics. Clin Microbiol Newsl. 2022;44(6):51-61. doi:10.1016/j.clinmicnews.2022.03.001
- Shah S, Hubscher E, Pelletier C, et al. Helicobacter pylori infection treatment in the United States: clinical consequences and costs of eradication treatment failure. Expert Rev Gastroenterol Hepatol. 2022;16(4):341-357. doi:10.1080/17474124.2022.2056015
- Hooi JKY, Lai WY, Ng WK, et al. Global prevalence of Helicobacter pylori infection: systematic review and meta-analysis. Gastroenterology. 2017;153(2):420-429. doi:10.1053/j.gastro.2017.04.022
- World Gastroenterology Organisation global guidelines: Helicobacter pylori. Updated May 2021. Accessed March 9, 2023. https://www.worldgastroenterology.org/guidelines/helicobacter-pylori/helicobacter-pylori-english
- Chey WD, Leontiadis GI, Howden CW, et al. ACG clinical guideline: treatment of Helicobacter pylori infection. Am J Gastroenterol. 2017;112(2):212-239. doi:10.1038/ajg.2016.563
- El-Serag HB, Kao JY, Kanwal F, et al. Houston Consensus Conference on testing for Helicobacter pylori infection in the United States. Clin Gastroenterol Hepatol. 2018;16(7):992-1002.e6. doi:10.1016/j.cgh.2018.03.013
- Lee YC, Dore MP, Graham DY. Diagnosis and treatment of Helicobacter pylori infection. Annu Rev Med. 2022;73:183-195. doi:10.1146/annurev-med-042220-020814
- Gupta S, Li D, El Serag HB, et al. AGA clinical practice guidelines on management of gastric intestinal metaplasia. Gastroenterology. 2020;158(3):693-702. doi:10.1053/j.gastro.2019.12.003
- Moayyedi P, Lacy BE, Andrews CN, et al. ACG and CAG clinical guideline: management of dyspepsia. Am J Gastroenterol. 2017;112(7):988-1013. doi:10.1038/ajg.2017.154
- Shah SC, Piazuelo MB, Kuipers EJ, et al. AGA clinical practice update on the diagnosis and management of atrophic gastritis: expert review. Gastroenterology. 2021;161(4):1325-1332.e7. doi:10.1053/j.gastro.2021.06.078
- Shah SC, Iyer PG, Moss SF. AGA clinical practice update on the management of refractory Helicobacter pylori infection: expert review. Gastroenterology. 2021;160(5):1831-1841. doi:10.1053/j.gastro.2020.11.059
- PyloPlus® UBT Kit for PyloPlus® UBT System. Package insert. Gulf Coast Scientific Inc; 2023. Accessed March 2, 2023. https://www.gulfcoastscientific.com/wp-content/uploads/2023/02/PPUBT-PACKAGE-INSERT-2-PAGE-FORMAT-REV_B_COMPLETE.pdf
- H. PYLORI CHEK™. Package insert. TECHLAB Inc; 2022. Accessed March 8, 2023. https://www.techlab.com/wp-content/uploads/2022/12/H-PYLORI-CHEK-PI-92-051-01-TL_12_2022-read.pdf
- Yang YX, Brill J, Krishnan P, et al. American Gastroenterological Association Institute guideline on the role of upper gastrointestinal biopsy to evaluate dyspepsia in the adult patient in the absence of visible mucosal lesions. Gastroenterology. 2015;149(4):1082-1087. doi:10.1053/j.gastro.2015.07.039
- Attumi TA, Graham DY. Follow-up testing after treatment of Helicobacter pylori infections: cautions, caveats, and recommendations. Clin Gastroenterol Hepatol. 2011;9(5):373-375. doi:10.1016/j.cgh.2010.12.025
Content reviewed 04/2023