Clinical outcome of pediatric collagenous gastritis: Case series and review of literature

Management of collagenous gastritis in children: Case series and literature review

Collagenous gastritis (CG) is a rare histopathological finding on gastric biopsies in children. It is associated with abdominal pain and iron deficiency anemia, usually not respondent to oral iron supplements. The aim of this study was to describe our experience in the management of pediatric patients with CG. Moreover, we propose to review the literature on this topic. We retrospectively reviewed all pediatric patients diagnosed with CG at our centre from January 2014 to January 2019. Three pediatric patients (2 F, mean age 12.3) were diagnosed with CG during the study period. Two presented with moderate and one with severe anemia. Symptoms were abdominal pain, asthenia and headache in two and asthenia and abdominal pain in one. All underwent upper and lower gastrointestinal endoscopy. All were firstly started with oral iron supplements with no benefit, principally due to poor compliance secondary to the worsening of the epigastric pain and proton pump inhibitor resistance. Therefore, they underwent ferric carboxymaltose (FCM) infusion with good clinical and laboratory response. Patients received a mean of two infusions/year, with stable hemoglobin levels and no adverse outcomes. Our review failed to identify a consistent response to specific treatments. Considering the apparent benign nature of the disease, symptomatic and supportive treatments are advisable. Iron deficiency anemia is largely present and therapy with oral iron supplements is not always successful. In our study, FCM infusion was effective in increasing the key blood indices in patients who poorly tolerated oral supplements.

Literature Review and a Relevant Case of Pediatric Collagenous Gastritis: A Rare but Important Etiology of Iron-Deficiency Anemia

An adolescent male with fatigue, weight loss, and iron-deficiency anemia failed to improve with iron supplementation and a gluten-free diet. Endoscopy revealed collagenous gastritis. Pediatric patients with refractory iron deficiency and family history of autoimmune disorders should be referred to pediatric gastroenterology for evaluation of collagenous gastritis and celiac disease.

Clinical and Pathologic Response to Vedolizumab in a Young Female Patient With Collagenous Gastritis

Collagenous gastritis is a rare form of gastritis that affects both children and adults. The underlying pathophysiology is not well-understood, and as a result, there are limited options for treatment. We report a case of a young female patient with chronic diffuse abdominal pain, nausea, regurgitation, and early satiety with esophagogastroduodenoscopy showing gastric erythema, atrophic gastric body, and significant gastric nodularity. Biopsies revealed focal erosion and increased subepithelial collagen deposition. She was successfully managed with intravenous vedolizumab infusions after initial therapy with topical budesonide did not result in clinical or endoscopic improvement.

Collagenous gastritis in children: A national cohort

BACKGROUND

Collagen gastritis is a rare disease that manifests in children mainly as isolated gastric involvement associated with martial deficiency anemia. There are no recommendations for the management and follow-up of these patients. We aimed to describe the clinical data, endoscopic findings, and treatments deployed in France's children with collagenous gastritis.

METHODS

All French pediatric gastroenterology centers and pediatric centers for rare digestive diseases (Centres de Maladies Rares Digestives) were contacted to collect cases of collagenous gastritis, defined on gastric biopsies and diagnosed before 18 years of age.

RESULTS

A total of 12 cases diagnosed (4 males and 8 females) between 1995 and 2022 could be analyzed. The median age at diagnosis was 12.5 years (7-15.2). The most frequent clinical presentation was abdominal pain (6/11) and/or nonspecific symptomatology attributed to anemia (8/10). Anemia was present in all children (11/11; Hb 2.8-9.1 g/dL). Nodular gastritis was present in 10 patients (antrum: 2; fundus: 4; in antrum and fundus: 4). All patients had a basement membrane thickening (from 19 to 100 μm). The treatments received were PPI (11), oral or intravenous martial supplementation (12), budesonide (1), and prednisone (1). Martial supplementation improved anemia in all cases. At discontinuation, nine of 10 patients had a recurrence of anemia.

CONCLUSION

Collagenous gastritis is an exceptional condition, clinically manifested in children as abdominal pain and iron deficiency anemia probably of hemorrhagic origin. Patients require long-term follow-up and monitoring of their disease to describe the risk of progression better.

Collagenous Gastritis: A Cause of Pediatric Iron Deficiency Anemia

Collagenous gastritis (CG) is a rare histopathological condition characterized by subepithelial collagen deposition and inflammatory infiltrates in the gastric mucosa. With less than 100 cases reported in current literature, clinical presentation is highly variable. We report a case of isolated CG in an 11-year-old girl who presented with a 6-month history of symptomatic severe iron deficiency anemia (nonexertional shortness of breath, palpitations, chest pain, and lethargy). CG is a rare condition in children require long-term follow-up and monitoring of their disease; and because of its rarity, a targeted treatment does not exist. The current therapeutic strategy is focused on symptom control and monitoring iron studies, in conjunction with regular follow-up.

Collagenous Gastritis: Characteristics and Response to Topical Budesonide

BACKGROUND AND AIMS

Collagenous gastritis (CG) is a rare disorder characterized by subepithelial collagen deposition in the stomach. Standard medications have been only moderately successful in treating CG. We report results of a large, retrospective, open-label noncontrolled study of topical budesonide for CG, with an aim of establishing an alternative therapy for the disease.

METHODS

We identified patients treated for CG at Mayo Clinic (2000-2017) with topically targeted budesonide (TTB) in 2 formulations: open-capsule budesonide or compounded immediate-release budesonide capsule. Demographic, clinical, biochemical, and histologic variables were assessed for all patients before and after treatment.

RESULTS

We identified 64 patients with CG (50 adults, 14 children). Most were female (68%), mean age was 41 ± 22.8 years, and body mass index was 23.1 ± 5.9 kg/m². In most pediatric patients, CG presented with abdominal pain and anemia; in adults, CG presented more often with weight loss (P < .001). Collagenous sprue or colitis were more common in patients >50 years of age (83%) vs those 19-50 years of age (27%) or <19 years of age (50%) (P < .001). Of the patients treated with TTB, 89% had a clinical response to TTB (42% complete, 46% partial), and 88% had a histologic response (53% complete, 33% partial).

CONCLUSIONS

Adults and children with CG have a wide variety of symptoms, and notably, TTB therapy produced clinical and histologic improvement after other therapy had failed.

Helicobacter pylori-negative Chronic Gastritis in Children: A Systematic Review

OBJECTIVES

To systematically review the current evidence on Helicobacter pylori-negative chronic gastritis including natural history, available therapies and outcomes.

METHODS

Articles providing data on the prevalence, treatment or outcomes of Helicobacter pylori-negative gastritis were identified through a systematic search in the MEDLINE and EMBASE databases. All original research articles from human studies until October 31, 2021, were included.

RESULTS

A total of 54 studies were included consisted of eosinophilic gastritis (n = 9), autoimmune gastritis (n = 11), collagenous gastritis (n = 16), focally enhanced gastritis (n = 6), lymphocytic gastritis (n = 5) and other causes including idiopathic gastritis and chronic renal failure related (n = 7). Most of the included studies were either cross-sectional or longitudinal cohorts except for collagenous gastritis, which mainly included case reports and case series. The prevalence of paediatric eosinophilic gastritis ranges between 5 and 7/100,000 and patients have generally favourable outcome with 50% to 70% clinical and histological response to either corticosteroids or elimination diets. Autoimmune gastritis and collagenous gastritis are extremely rare entities, commonly present with refractory iron deficiency anaemia, while lymphocytic gastritis is relatively common (10%-45%) in children with coeliac disease. Data on treatments and outcomes of autoimmune, collagenous, and focally enhanced gastritis are lacking with limited data implying poor response to therapy in the former 2 diagnoses.

CONCLUSIONS

Helicobacter pylori-negative gastritis is uncommonly reported, mainly in small cohorts, mixed adult-paediatric cohorts or as sporadic case reports. As common symptoms are not specific, thus not always result in an endoscopic evaluation, the true prevalence of these distinct disorders may be underestimated, and thus under reported.

Collagenous gastroduodenocolitis in a Korean adolescent: first pediatric case report in Asia

Collagenous gastritis (CG) is a rare disease diagnosed histologically by the subepithelial deposition of collagen bands thicker than 10 µm and the infiltration of inflammatory mononuclear cells in the lamina propria. The definite pathophysiology is yet to be elucidated. However, recent studies have suggested that the collagen deposition may be the result of a reparative process in response to an earlier inflammatory, autoimmune, infectious, or toxic insult. CG is divided into the pediatric- and adult-type. While the pediatric-type is limited to the stomach, the adult-type involves not only the stomach but also the intestine and/or colon. We report a rare case of adult-type CG in a 15-year-old boy who initially presented with abdominal pain and iron-deficiency anemia. Esophagogastroduodenoscopy (EGD) revealed findings suspicious for Helicobacter pylori (H. pylori) gastritis. Although histology did not reveal the organism, campylobacter-like organism (CLO) test was positive. Based on the diagnosis of suspicious H. pylori gastritis, eradication was conducted using the triple drug regimen. However, symptoms of intermittent abdominal pain persisted and diarrhea newly developed one year later. Histologic results from biopsies from the stomach, duodenum, and colon revealed findings compatible with CG, collagenous duodenitis (CD), and collagenous colitis (CC). This is the first pediatric case of collagenous gastroduodenocolitis (CGDC) reported in Asia. It is no longer assumed that adult-type and pediatric-type CG should be classified as an independent disease, but should be considered as similar diseases on a continuous spectrum. Therefore, children and adolescents diagnosed with CG should also consider undergoing a colonoscopy for the evaluation of possible coexisting CC when concurrent lower gastrointestinal symptoms are present. Moreover, considering the possibility of negative findings on the first endoscopy, repeat endoscopy should be considered when symptoms persist.

Pediatric Collagenous Gastritis: Clinical and Histologic Outcomes in a Large Pediatric Cohort

OBJECTIVE

The aim of the study was to present the clinical characteristics, treatment, and outcomes of pediatric collagenous gastritis (CG).

METHOD

This is a retrospective cohort study. Patients were identified via query of the institutional pathology database. Clinical data was obtained by review of medical records.

RESULTS

Forty patients (57.5% female) were identified, mean age 11.3 ± 3.7 years (2-16years). Isolated CG was present in 66.7%, coexisting collagenous duodenitis (CD) in 17.5%, collagenous colitis (CC) in 7.5%, and collagenous ileitis in 2.5%. Atopic comorbidities were found in 25%, autoimmune comorbidities in 12.5%.

PRESENTING SYMPTOMS

Abdominal pain (77.5%), vomiting (65%), anemia (57.5%), nausea (55.5%), diarrhea (32.5%), anorexia (25.0%), weight loss (25%), gastrointestinal bleed (22.5%), poor growth (20%), poor weight gain (12.5%).

ENDOSCOPIC FINDINGS

All had abnormal endoscopic findings on esophago-gastro-duodenoscopy (EGD), most commonly gastric nodularity (77.5%), visible blood (20%), erosions/superficial ulcerations (10%), ulcers (7.5%). Histologically, all patients had increased subepithelial collagen deposition.

TREATMENT

A variety of medications aimed towards inflammation and symptomatic treatment were used. Patients with anemia received iron supplementation and responded. Otherwise, there was no significant association of clinical or histologic improvement with specific treatments.

CLINICAL AND HISTOLOGIC OUTCOMES

87.5% reported improvement or resolution of symptoms at the last follow-up (34.8 ± 27.0 months). Persistent sub-epithelial collagen was noted in 73.1% on the last EGD.

CONCLUSIONS

Despite persistent findings of increased sub-epithelial collagen deposition during the follow-up period, most patients with CG show remission or resolution of clinical symptoms. Anemia responds to iron supplementation in all patients.

Collagenous Gastritis in Children: Incidence, Disease Course, and Associations With Autoimmunity and Inflammatory Markers

Collagenous gastritis (CG), a rare disorder of unknown etiology, has been postulated to have immune-mediated mechanisms. We investigated (i) the incidence and prevalence of CG in a pediatric population; (ii) the clinical, endoscopic, and histologic characteristics of childhood-onset CG; and (iii) the evidence for autoimmunity and/or inflammatory activity in these patients.

Collagenous Gastritis Masquerading as Eosinophilic Gastritis

A 11-year-old boy presented to the gastroenterology clinic after a 5-month history of fatigue, pallor, intermittent abdominal pain, and iron-deficiency anemia. Although the initial upper endoscopy was visually normally, the histological assessment was suggestive of eosinophilic gastritis. After multiple scopes and failed therapies, histologic analysis revealed a focus of thickened subepithelial collagen deposition suggestive of collagenous gastritis. A retrospective review of gastric biopsies using Gomori trichrome stain revealed previously unappreciated collagen deposition. This case report illustrates the benefit of performing trichrome stain on gastric biopsies in the setting of persistent or isolated gastric eosinophilia or iron deficiency anemia.

Pediatric Collagenous Gastroenterocolitis Successfully Treated with Methotrexate

A two-and-one-half-year-old previously healthy female presented with a ten-week history of watery diarrhea, nonbilious and nonbloody emesis, and low-grade fevers. She was found to have severe hypoalbuminemia and hypogammaglobulinemia. Her symptoms persisted, and she became dependent on parenteral nutrition. Biopsies obtained during subsequent endoscopic and colonoscopic studies revealed findings consistent with collagenous gastroenterocolitis. She responded to an empiric course of prednisone, but her symptoms recurred shortly after transitioning to oral budesonide. After successful reinduction with intravenous prednisone, intramuscular methotrexate was initiated. She remained asymptomatic during a 15-month course of therapy, and she continued to do well clinically until approximately nine months after weaning off methotrexate. At that point, she experienced a recurrence of diarrhea, and repeat endoscopic evaluation confirmed collagenous colitis. This responded nicely to a short course of oral budesonide, and she has since remained asymptomatic and off any therapy.

Diagnosis of chronic anaemia in gastrointestinal disorders: A guideline by the Italian Association of Hospital Gastroenterologists and Endoscopists (AIGO) and the Italian Society of Paediatric Gastroenterology Hepatology and Nutrition (SIGENP)

Anaemia is a common pathologic condition, present in almost 5% of the adult population. Iron deficiency is the most common cause; other mechanisms can be involved, making anaemia a multi-factorial disorder in most cases. Anaemia being a frequent manifestation in the diseases of the gastrointestinal tract, patients are often referred to gastroenterologists. Furthermore, upper and lower endoscopy and enteroscopy are pivotal to the diagnostic roadmap of anaemia. In spite of its relevance in the daily clinical practice, there is a limited number of gastroenterological guidelines dedicated to the diagnosis of anaemia. For this reason, the Italian Association of Hospital Gastroenterologists and Endoscopists and the Italian Society of Paediatric Gastroenterology, Hepatology and Nutrition commissioned a panel of experts to prepare a specific guideline on anaemia and its diagnostic roadmap in the gastroenterological scenario. The panel also discussed about the potential involvement of gastroenterologists and endoscopists in the management of patients with anaemia, with particular attention to the correct use of investigations. The panel paid particular attention to practical issues with the aim to support gastroenterologists in their clinical practice when dealing with patients with anaemia.

Three case reports of collagenous gastritis in children: Lessons for an endoscopic and histologic approach to mucosal nodularity of the stomach

RATIONALE

Collagenous gastritis (CG) is a rare form of chronic gastritis defined histologically by a thickened subepithelial collageneous band in the lamina propria. However, the clinical features and endoscopic findings of CG have not been clearly established in the pediatric population.

PRESENTING CONCERNS

We report the cases of 3 children who presented with intractable anemia and minimal or no gastrointestinal (GI) symptoms and were followed up without definitive diagnosis determination even through diagnostic endoscopic evaluations.

DIAGNOSES

On repeated endoscopic examination, we determined thickened subepithelial collagen band, confirmed by Masson trichrome staining using targeted biopsies of the intervening mucosa between the prominent nodular lesions.

INTERVENTIONS

Under the diagnosis of CG, a course of steroid was administrated in 1 patient, while all patients continued oral iron replacement therapy.

OUTCOMES

All 3 patients remained asymptomatic and their anemia was alleviated with continued administration of oral iron.

MAIN LESSONS

We recommend early endoscopic evaluation for patients with unexplained anemia, emphasizing a high index of suspicion for CG, despite the absence of definitive GI symptoms. Targeted gastric biopsies should be performed in the depressed mucosa surrounding the nodules, as well as the nodules themselves, to confirm CG, when presented with nodular gastric mucosa in endoscopy.

Collagenous Gastritis, a Rare Cause of Dyspepsia Resistant to Treatment; A Case Report

Collagenous gastritis is hardly ever found in children and adults. Based on the extent of collagenous changes in the bowel, various symptoms may develop including iron deficiency, anemia, and abdominal pain in most of the patients.

We present a 30-year-old man with persistent abdominal pain and anemia due to collagenous gastritis.

Pediatric Collagenous Gastritis and Colitis: A Case Series and Review of the Literature

INTRODUCTION

Collagenous gastritis is a rare disease characterized by the subepithelial deposition of collagen bands. Two phenotypes of the disease have been described: a pediatric-onset and an adult-onset type. The adult-onset form is associated with collagenous colitis and autoimmune disorders. No effective treatment has been identified to date.

OBJECTIVE

We aim to describe the clinical features and outcomes of patients in our cohort and provide a summary of published pediatric cases with collagenous gastritis and colitis reported to date to gather information that will contribute to improved knowledge of this rare condition.

METHODS

A retrospective chart review of all patients with collagenous gastritis and/or colitis who were treated at the Royal Children's Hospital, Melbourne, was performed. A literature review was also conducted.

RESULTS

A total of 12 cases of collagenous gastritis were reviewed. Three of 12 (25%) patients had associated collagenous colitis. The most common clinical presentation was iron deficiency anemia. Nine (75%) patients were followed up, and repeat endoscopies were performed in 8 (67%). Iron deficiency anemia resolved in all patients on oral iron supplementation. Histologic improvement was only identified in one patient with the adult phenotype who had been treated with oral corticosteroids and azathioprine.

CONCLUSIONS

Collagenous gastritis is a rare condition in children. A small proportion of children develop features of the "'adult" phenotype at a very young age. Patients with collagenous gastritis require long-term follow-up and monitoring of their disease. Further randomized clinical trials are needed to establish an effective therapeutic strategy.

Anemia revealing a collagenous gastritis in a young Tunisian man

Collagenous gastritis is a rare entity, characterized by the deposition of a subepithelial collagenous band with an inflammatory infiltrate in the mucosa. We report the first Tunisian case revealed by severe anemia. Lesions were limited to the stomach and remained unchanged on 3 series biopsies during a 24 month follow up despite treatment with corticosteroids. The cause of the disease remains unknown; our findings suggest that lesions of collagenous gastritis may result from a local immune process.

Collagenous Gastritis and Helicobacter pylori Infection: A Mere Coincidence?

A 21-year-old woman presented to our clinic after 7 years of abdominal pain, diarrhea, and iron-deficiency anemia. Initial upper endoscopy revealed severe inflammation and nodularity of the gastric body and active Helicobacter pylori infection. After eradication therapy, esophagogastroduodenoscopy showed gastric atrophy with nodularity resolution. Histopathology revealed scattered plasma cells, eosinophils, and collagen deposition suggestive of collagenous gastritis. H. pylori can induce proinflammatory cytokines, resulting in fibroblast upregulation. Collagenous gastritis may be caused by an inflammatory response associated with type I, II, and III collagen. Although further research is warranted, we hypothesize that chronic inflammation from H. pylori may lead to collagenous gastritis.

[Collagenous gastritis and colitis in a 10-year-old girl]

There are few data in the literature on microscopic gastritis and colitis in the pediatric population. The diagnosis is often made after the occurrence of complications. We report the case of a 10.5 year-old girl for whom the diagnosis was made several years after the initial symptoms. Test for infections, inflammation, and auto-immunity yielded normal results. Upper endoscopy and colonoscopy revealed an abnormal mucosa. However, histology showed microscopic inflammation and fibrotic lesions in the lamina propria, and a thick subepithelial collagenous band. This led to the diagnosis of collagenous gastritis and colitis. Budesonide treatment resulted in the cessation of diarrhea and significant weight gain. Treatment by oral budesonide indeed seems to be highly effective but relapses are frequent when the treatment is stopped. This case shows the importance of being vigilant regarding transit disorders with impact on growth kinetics. Upper endoscopy and colonoscopy need to be carried out when children have organic diarrhea with normal blood tests.

Collagenous gastroduodenitis with recurrent gastric ulcer in 12-year-old girl

This report describes a rare case of collagenous gastroduodenitis found in a 12-year-old Japanese girl who had recurrent hematemesis. Gastrointestinal endoscopy showed many lotus leaf-like lesions on the gastric mucosa surrounded by atrophic gastric mucosa in the antrum, with a cobblestone appearance and a scarred duodenal ulcer in the duodenal bulb. A biopsy of the gastric mucosa indicated subepithelial collagen band. The patient was treated with H2-blockers for her symptoms for 4 years following the endoscopic findings. Follow-up endoscopy showed the same appearance as before. The pathology, however, showed a more prominent subepithelial collagen deposition. To make the correct diagnosis, it is critical to know from which part the pathological biopsy specimens were taken because there were numerous collagen bands in the atrophic membrane. It is important to monitor the patient regularly for evaluation of the etiology, pathogenesis and prognosis of this rare disease.

Chronic gastritis - an update

Helicobacter pylori is the main aetiologic factor for chronic gastritis worldwide. The degree of inflammation and the evolution of this form of chronic gastritis can vary largely depending on bacterial virulence factors, host susceptibility factors and environmental conditions. Autoimmune gastritis is another cause of chronic inflammation in the stomach, which can occur in all age groups. This disease presents typically with vitamin B12 deficiency and pernicious anaemia. The presence of anti-parietal cell antibodies is highly specific for the diagnosis. The role of H. pylori as a trigger for autoimmune gastritis remains uncertain. Other rare conditions for chronic gastritis are chronic inflammatory conditions such as Crohn's disease or on the background of lymphocytic or collagenous gastroenteropathies.

Collagenous gastroduodenitis coexisting repeated Dieulafoy ulcer: A case report and review of collagenous gastritis and gastroduodenitis without colonic involvement

Collagenous gastritis (CG) is a rare disorder characterized by the thick collagenous subepithelial bands associated with mucosal inflammation. There have been approximately fifty reports in the literature since it was first described in 1989. According to previous reports, CG is heterogeneous and classified into two groups-(1) cases limited to the gastric mucosa in children or young adults, and (2) CG associated with collagenous colitis in elderly adults presenting with chronic watery diarrhea. In Japan, only nine previous cases were reported, and all of them were young adults. We report a case of CG with collagenous duodenitis in a 22-year-old female. She had repeated upper gastrointestinal bleeding from a Dieulafoy lesion of the fornix, but had no symptoms of malabsorption or diarrhea. Endoscopic findings revealed striking nodularity with a smooth islet-shaped normal area in the antrum and the body. The pathological findings of nodular mucosa showed the deposition of collagen bands just under the mucoepithelial lesion. In addition, she had collagenous duodenitis in part of the bulbs, and a colonoscopy showed no abnormalities. We provide a literature review of CG and collagenous gastroduodenitis without colonic involvement.

Collagenous colitis associated with protein losing enteropathy in a toddler

Collagenous mucosal inflammatory disease is a rare gastrointestinal disorder that involves the columnar lining of gastric and intestinal mucosa and is characterized by a distinct subepithelial collagen deposition. Recent clinical and pathological evidence have indicated that collagenous mucosal inflammatory disease can be extensive disease that may concomitantly involve several gastrointestinal sites at the same time. This entity, however, occurs infrequently in children. It is even less common to find concomitant depositions of collagen in the mucosa of gastrointestinal sites other than the colon. Only two cases in pediatric literature reported concomitant involvement, one with gastric and colonic involvement and the other one with gastroduodenocolitis. We are reporting a 15-month-old boy who presented with severe diarrhea and diffuse edema secondary to hypoalbuminemia. Further testing documented protein losing enteropathy (PLE) associated with collagenous colitis.

A case of collagenous gastritis resembling nodular gastritis in endoscopic appearance

A 25-year-old Japanese female was referred to our clinic for the investigation of moderate iron-deficiency anemia and epigastralgia. Endoscopic examination showed diffuse mucosal nodules in the gastric body resembling nodular gastritis, but this pattern was not observed in the antrum. Histology of the gastric biopsies taken from the gastric body showed mild atrophic mucosa with chronic active inflammation. Some of the biopsy specimens showed deposition of patchy, band-like subepithelial collagen. Four years later, the patient showed no clinical symptoms and signs. A follow-up endoscopic examination showed similar findings, which mimicked pseudopolyposis or a cobblestone-like appearance. The biopsy specimens from the depressed mucosa between the nodules revealed a thickened subepithelial collagen band with no improvement, which led to a diagnosis of collagenous gastritis. Treatment with oral administration of proton-pump inhibitors and histamine-2-receptor antagonists had proved ineffective. To make a correct diagnosis of collagenous gastritis, we should determine the characteristic endoscopic findings and take biopsies from the depressed mucosa between the nodules.