Alejandro Llanos-Chea

We report the case of a 19‐year‐old White male diagnosed with familial adenomatous polyposis (FAP), Gardner's syndrome (GS) phenotype, status post total colectomy, who developed progressive dysphagia and weight loss. He was diagnosed with achalasia based on imaging and esophageal manometry. The patient underwent a Heller myotomy with the resolution of symptoms. To date, no previous literature has reported on concurrent FAP or GS and achalasia. Although FAP and achalasia are both rare conditions with no previously known concurrent occurrence, association, or described syndrome, it is important to be vigilant of this new case report finding. One must also consider the increased risk of malignancy in patients with achalasia in addition to the significant risk of malignancy in patients with FAP/GS.

Purpose of review: This is an overview of the effects of COVID-19 in the gastrointestinal tract in children, and current evidence of the impact of COVID-19 in pediatric patients with chronic gastrointestinal conditions, including inflammatory bowel disease (IBD), chronic liver disease, and disorders of the gut-brain interaction. Recent findings: Children with COVID-19 have a milder course and more favorable outcomes than adults, even in those with immunosuppression due to IBD or liver transplantation. Children with chronic gastrointestinal conditions do not have worse clinical outcomes than healthy children and infection itself has not been linked to an increased incidence of conditions such as IBD and celiac disease, but results regarding post-infectious irritable bowel syndrome are mixed. Summary: Research specific to pediatrics is needed, particularly in post-infectious disorders of the gut-brain interaction (PI-DGBIs) and long COVID-19. Data extrapolated from adult trials may not apply to children, as their clinical course is different. PI-DGBIs and long COVID-19 require special attention, as they represent a major morbidity burden in children.

Background Inflammatory bowel diseases (IBD) are often treated with anti-tumor necrosis factor alpha (anti-TNFα) medications. Concomitant treatment of IBD with anti-TNFα agents and immunomodulators appears to be associated with an increased risk for lymphoma. Methods Patients who developed lymphoma while on monotherapy with an anti-TNFα agent were identified at three centers. Institutional Review Board approval was obtained. Results Five adolescents and young adult patients with pediatric-onset IBD who were treated with infliximab (IFX) without exposure to thiopurines were subsequently diagnosed with lymphoma. Three of the five patients had bone involvement at presentation. Epstein–Barr virus was positive in 2 cases. Median time from diagnosis of IBD and exposure to IFX prior to diagnosis of lymphoma was 5 and 4.3 years, respectively. Conclusions This case series reports long-term follow-up for young patients with IBD who were treated with IFX monotherapy and developed lymphoma. Three of the five patients had bone involvement. In general, the risk of lymphoma following exposure to anti-TNFα medications alone remains low, but the incidence of primary bone lymphomas in IBD has not been reported. Studies examining longer exposure times may be needed to determine the true lymphoma risk in patients treated with IFX monotherapy.

Background: One of the criteria for functional constipation (FC) in Rome IV criteria is the presence of hard or painful bowel movements. In adults and children, the Rome IV criteria recommend the use of the Bristol Stool Scale (BSS). This scale is thought not to be appropriate for evaluation of stool consistency in young children. The Brussels Infant and Toddler Stool Scale (BITSS) was developed as a scale for children wearing diapers. There are no prior studies comparing BITSS with BSS in a clinical setting. Our main aim was that BITSS behaves differently than the BSS as it reflects better stool characterization by parents.Methods: Surveys were provided to parents of participants in two cities from Colombia which included the Rome IV‐validated questionnaire and stool consistency assessment using pictures for BSS and BITSS.Key Results: A total of 666 responses were obtained for non‐toilet‐trained children, mean age was 16.6 months. Detection for normal stools was higher using BSS (58.6%) when compared to BITSS (13.6%), and conversely was more likely to be abnormal through BITSS (86.4%) than BSS (41.4%) (p < 0.0001). BITSS (57.4%) was better than BSS (25.3%) identifying hard stools in FC (p = 0.000). For hard stools per parental classification, BITSS’ definition was better than BSS (75.8% vs 44%, respectively, p = 0.000).Conclusions: The BITSS and BSS behave differently. The BITSS seems to be more sensitive to detect hard stools and FC than BSS. More studies are needed to better define whether BITSS is appropriate to replace BSS in non‐toilet‐trained infants and toddlers.

Functional gastrointestinal disorders (FGIDs) and functional abdominal pain disorders (FAPDs) are common in pediatric patients. The prevalence of FGIDs using the Rome IV criteria ranges from 21.1% to 25.0% in children. The Rome IV criteria specify that the decision of testing is left to the clinician, giving him or her freedom to decide on the necessary workup. The clinician should consider all of the functional and organic diseases that manifest with chronic abdominal pain, as well as alarm features that should prompt testing. Societal guidelines and reports do not recommend routine evaluations for FAPDs, particularly in the absence of alarm features. Studies have reported variable results upon assessing the diagnostic yields of different tests. Furthermore, these evaluations considerably increase costs for the health care system. This article examines the current evidence on the utility of diagnostic testing in pediatric patients with FAPDs.

An adolescent male presented with recurrent episodes over several years of severe iron deficiency anemia and associated severe thrombocytopenia. The anemia was secondary to chronic blood loss due to ulceration at the site of an ileocolonic anastomosis performed during infancy. We were able to demonstrate complete resolution of thrombocytopenia with the administration of iron, and without using steroids, intravenous immunoglobulin, or platelet transfusions. This is the first reported case of an individual with multiple episodes over several years of thrombocytopenia secondary to recurrent severe iron deficiency anemia, illustrating a predisposition to this complication in a unique patient.

In children, functional gastrointestinal disorders (FGIDs) are common at all ages. Consumption of certain foods, particularly gluten, is frequently associated with the development and persistence of FGIDs and functional abdominal pain disorders (FAPDs) in adults and children. However, this association is not well defined. Even without a diagnosis of celiac disease (CD), some people avoid gluten or wheat in their diet since it has been shown to trigger mostly gastrointestinal symptoms in certain individuals, especially in children. The incidence of conditions such as non-celiac gluten sensitivity (NCGS) is increasing, particularly in children. On the other hand, CD is a chronic, autoimmune small intestinal enteropathy with symptoms that can sometimes be mimicked by FAPD. It is still unclear if pediatric patients with irritable bowel syndrome (IBS) are more likely to have CD. Abdominal, pain-associated FGID in children with CD does not seem to improve on a gluten-free diet. The threshold for gluten tolerance in patients with NCGS is unknown and varies among subjects. Thus, it is challenging to clearly distinguish between gluten exclusion and improvement of symptoms related solely to functional disorders.

Neutrophil influx into the intestinal lumen is a critical response to infectious agents, but is also associated with severe intestinal damage observed in idiopathic inflammatory bowel disease. The chemoattractant hepoxilin A₃, an eicosanoid secreted from intestinal epithelial cells by the apically restricted efflux pump multidrug resistance protein 2 (MRP2), mediates this neutrophil influx. Information about a possible counterbalance pathway that could signal the lack of or resolution of an apical inflammatory signal, however, has yet to be described. We now report a system with such hallmarks. Specifically, we identify endocannabinoids as the first known endogenous substrates of the apically restricted multidrug resistance transporter P-glycoprotein (P-gp) and reveal a mechanism, which we believe is novel, for endocannabinoid secretion into the intestinal lumen. Knockdown or inhibition of P-gp reduced luminal secretion levels of N-acyl ethanolamine–type endocannabinoids, which correlated with increased neutrophil transmigration in vitro and in vivo. Additionally, loss of CB2, the peripheral cannabinoid receptor, led to increased pathology and neutrophil influx in models of acute intestinal inflammation. These results define a key role for epithelial cells in balancing the constitutive secretion of antiinflammatory lipids with the stimulated secretion of proinflammatory lipids via surface efflux pumps in order to control neutrophil infiltration into the intestinal lumen and maintain homeostasis in the healthy intestine.