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Craig Friesen: Understanding Food Allergies and Food Intolerance in DGBIs

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Dr. Craig Friesen gave our group an excellent update on food allergy and disorders of brain-gut interaction (DGBIs).  His main disclosure was that he is not an allergist. My notes below may contain errors in transcription and in omission. Along with my notes, I have included many of his slides.

Key points:

  • Food allergies are common affecting 6-10% of the population. In infants, milk and egg are common allergens. Nut allergies are more frequently seen in children
  • There are likely hundreds of genes that can predispose towards allergies
  • Food exposures, especially in the 4-6 month range, have been associated with a lower risk of food allergies
  • Food trigger symptoms are present in most patients with DGBIs; however, the lines between immune mechanisms and non-immune mechanisms are often blurry
  • Food allergy testing (skin prick testing, IgE-based blood tests) is not recommended in the absence of systemic symptoms due to poor specificity (perhaps ~10%). Obtaining a careful history is a very important part of determining allergies. Double-blind challenges, which are rarely done, are still considered “gold standard” for diagnosis
  • Mucosal endoscopic provocation (research tool) often discloses localized immune reaction; it does not correlate with skin prick testing or IgE-based blood tests
  • After prior sensitization/food allergies, stressful conditions may create similar symptoms as allergic exposures. This can be mediated by histamine and tryptase/mast cells
  • It is rare for food allergen restriction to “fix” a DGBI. Occasionally, food allergies may be part of the problem. Dietary restrictions may lead to weight loss and contribute to ARFID
  • IgG-based allergy testing (widely available) is not recommended; IgG antibodies are usually indicative of tolerance
  • Environmental pollen counts are associated with increased DGBI symptoms, increased mucosal eosinophils, and less sleep
  • Environmental allergen testing can sometimes be helpful in identifying cross-reacting foods
  • Alpha-gal syndrome. Consider testing in those with symptoms triggered by meat ingestion, and those with refractory symptoms. In pediatric patients, often no rash is identified and many will ‘outgrow’ allergy
  • Oral immunotherapy can be effective in improving tolerance for allergic foods; however, up to 70% will redevelop intolerance
  • When mucosal eosinophilia is identified, there are a number of potential treatments including dietary restrictions, mast cell stabilizers, antihistamines, and steroids

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Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

CT Imaging and Projected Cancer Risks: 2025 Analysis

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Smith-Bindman R, Chu PW, Azman Firdaus H, et al.  JAMA Intern Med. Published online April 14, 2025. doi:10.1001/jamainternmed.2025.0505. Open Access! Projected Lifetime Cancer Risks From Current Computed Tomography Imaging

Methods: Lifetime radiation-induced cancer incidence and 90% uncertainty limits (UL) were estimated by age, sex, and CT category using National Cancer Institute software based on the National Research Council’s Biological Effects of Ionizing Radiation VII (BEIR VII) models and projected to the US population using scaled examination counts.

Key findings:

  • Ninety-three million CT examinations were performed in 61 510 000 patients in the United States in 2023, including an estimated 3,069,000 CTs (3.3%) in 2,570,000 children (4.2%) and 89,931,000 CTs (96.7%) in 58,940,000 adults (95.8%) 
  • In this risk model, the 93 million CT examinations performed in 62 million patients in 2023 were projected to result in approximately 103,000 future cancers
  • Estimated radiation-induced cancer risks were higher in children and adolescents, yet higher CT utilization in adults accounted for most (93,000) radiation-induced cancers
  • “If current practices persist, CT-associated cancer could eventually account for 5% of all new cancer diagnoses annually”

Discussion: “The projected number of radiation-induced cancers in this analysis is 3 to 4 times higher than the earlier assessment of CT exposure for several reasons”

  • CT use is 30% higher today than in 2007
  • Dose modeling in this study accounted for multiphase scanning
  • Substantially higher organ doses in this study were reconstructed using newer dosimetry methods
  • More granular CT categories reflecting imaging indications that have important dose differences
  • “Many of the model assumptions were conservative” and could underestimate the risk

My take (borrowed from authors): “Even very small cancer risks will lead to a significant number of future cancers given the tremendous volume of CT use in the United States…CT could be responsible for approximately 5% of cancers diagnosed each year. This would place CT on par with other significant risk factors, such as alcohol consumption (5.4%) and excess body weight (7.6%)”

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Kiawah Beach, SC

Jose Garza: Belching, Bloating and Best Advice

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Recently Dr. Garza gave our group an excellent lecture. It is always great learning more about how the GI tract really works and what is going wrong when patients are having symptoms. I have taken some notes and shared some slides. There may be inadvertent omissions and mistakes in my notes.

Physiology:

  • Air in the GI tract needs to either be expelled from mouth, be absorbed or be expelled rectally. Nitrogen gas is not well-absorbed. Bacteria in GI tract can contribute to gas production and can also absorb gas.
  • Only about 23% of GI tract air is expelled rectally as gas. Most gas is absorbed and can be expelled from the lungs subsequently.
  • GI tract makes adjustments after swallowing air to help with comfort. This includes raising of the diaphragm. Toddlers frequently have aerophagia but infrequently have symptoms due to distention. Symptoms may worsen in teens/older individuals due to not allowing gas passage

Bloating:

  • Bloating is a sensation that can occur with and without distention.
  • Up to 85% of patients with DGBIs c/o bloating
  • Reasonable to check for celiac disease and possibly other tests if alarm symptoms like bilious vomiting, weight loss and poor growth
  • Increased air in the small bowel is rare and often indicative of dysmotility
  • Elegant studies with CT scan have shown that the typical increase in excess gas during bloating symptoms is only 22 mL. With pseudoobstruction, excess volume of gas is around 3000 mL.
  • pH-impedance is good at detecting aerophagia which often contributes to bloating. Aerophagia prevalence was 3.66% in one study
  • The amount of air from bacterial overgrowth (SIBO) is usually NOT enough to cause most of the reported symptoms of bloating (though may be a contributing factor).
  • A lot of bloating symptoms are due to increased sensitivity and ‘weird gas handling.’ The latter could include compression of diaphragm rather than elevation.
  • Diets (eg lower fructan) can decrease gas but likely also work in other ways. Diets also have side effects and this needs to be carefully considered due to potential issues with eating disorders/ARFID
  • Treat constipation IF PRESENT
  • Diaphragmatic breathing, CBT, neuromodulators and peppermint oil are potential treatment options
  • Increased activity helps with bloating and gas passage

Belching:

  • Descriptions of belching date back more than a hundred years
  • Most belching is normal. Most belching is due to gastric belching and is physiologic
  • Supragastric belching is abnormal. Hallmarks are frequent symptoms and can be associated with worsening reflux and rumination
  • Differences between gastric and supragastric belching can usually be distinguished with clinical presentation (see below). Manometry findings are distinctive between the two. With supragastric belching, With supragastric belching, the air that is expelled is from the esophagus. With gastric belching, air that has reached the stomach is expelled.  
  • Main treatments for supragastric belching are diaphragmatic breathing, and CBT

Inability to Belch:

  • In patients unable to burp, many have retrograde cricopharyngeus dysfunction. This is due to dysfunction of upper esophageal sphincter which had increased pressure and not allowing air in the esophagus to escape. This, in turn, causes discomfort and gurgling noises. While this disorder was reported in 1987, more widespread recognition has occurred since 2019
  • Manometry should be done prior to botox therapy which results in improvement in most patients

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Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Impact of Testing (or No Testing) for Rumination Syndrome Outcomes

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JS Khoo et al. J Pediatr Gastroenterol Nutr. 2025;80:611–616. Impact of diagnostic testing on outcomes of children with rumination syndrome

Background: “A prior study from our institution showed that many patients undergo extensive diagnostic testing, which is associated with high financial cost with low clinical yield and delay in diagnosis.”

Methods: This was a retrospective study with 152 children (60% female, median age of diagnosis 13 years) with rumination syndrome (RS). 22 patients (14%) had diagnostic testing that confirmed RS.

Key findings:

  • The confirmatory testing group was more likely to need supplemental nutrition (p ≤ 0.001) and to receive intensive treatment (68% vs 24%) (p < 0.001)
  • After treatment, the proportion of patients without vomiting increased in both groups without a statistically significant difference between the two groups or needing supplemental nutrition.

Discussion Points:

“Our findings reveal that despite advancements in testing methodologies, undergoing diagnostic testing and receiving a positive result for RS is not associated with improved outcomes, specifically in cessation of vomiting, after treatment. In situations where patients and caregivers have difficulty accepting the clinical diagnosis, selective testing may be justified as acceptance of the diagnosis is a crucial aspect of the therapeutic plan for all gut-brain interaction disorders.”

Limitations included selection bias. While there were not overt differences in outcomes, the confirmatory testing group required more intensive treatment. As such, the testing may have some benefit in this group (though this was not identified in this retrospective study).

My take (borrowed in part from the authors): “We recommend that clinicians avoid diagnostic testing in children who clearly meet symptom-based criteria for RS and accept the diagnosis.”

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Train bridge near Chickamauga dam (Tennessee River).
There is a blue heron about to take flight due to the oncoming train

Understanding the Economic Burden of Inflammatory Bowel Disease

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J Burisch et al. Clin Gastroenterol Hepatol 2025; 23: 386-395. Open Access! The Cost of Inflammatory Bowel Disease Care: How to Make it Sustainable

This article is a terrific review of care cost drivers in inflammatory bowel disease (IBD) but it does not actually have useful information on how to make the costs of care sustainable.

Key points:

  • The most recent data from the United States (U.S.) estimated that the prevalence of IBD
    was 0.7% of the population, representing 2.39 million individuals living with IBD…the annual cost of IBD in the U.S. approximates $50 billion
  • All studies demonstrated a shift over time from costs associated with hospitalizations to costs of medications
  • The costs of prescription drugs for IBD vary significantly worldwide… A particular outlier among high-income countries is the U.S., where manufacturers set prices freely. The lack of
    nationwide price regulation, coupled with the fragmentation of the U.S. health care system and prolonged market exclusivity periods, result in U.S. drug prices that exceed, on average, international prices by several-fold…Even when insurers are successful at negotiating discounts, patients seldom benefit, as costsharing paid at the point-of-sale is based on the full, non-discounted price
  • Using a “top-down” clinical paradigm, guidelines suggest starting biologic medications early to induce remission of moderate-to-severe IBD, thereby reducing risk of complications, surgeries, and hospitalizations and improving quality of life.55,58 A randomized controlled
    trial demonstrated a clear benefit in steroid-free and surgery-free remission among patients randomized to top-down vs step-up care (79% vs 15%; P < .0001) [PROFILE study]

In terms of improving cost sustainability, here is what the authors propose “Strategies for cost reduction in the clinical treatment of IBD”:

My take: This article highlights the cost drivers in IBD but does not identify a path that appears to help address affordability.

This article is one of 11 articles in special issue discussing the future of IBD care.

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Treatment Disparities in Adult vs. Pediatric IBD Care Related to Provider Specialization

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JD Lewis et al. Clinical Gastroenterology and Hepatology. 2024; Volume 22, Issue 12, 2475 – 2486.e14. Open Access ! Provider Specialization in Inflammatory Bowel Diseases: Quality of Care and Outcomes

Methods:  This was a retrospective cohort of newly diagnosed patients with IBD using data from Optum’s deidentified Clinformatics Data Mart Database (2000–2020). The study included 772 children treated by 493 providers and 2864 adults treated by 2076 providers.

Key findings:

  • In adults, care from an IBD-focused provider was associated with more use of biologics, combination therapy, and imaging and endoscopy, and less mesalamine use for Crohn’s disease (P < .05 for all comparisons)
  • In children, none of the associations between provider focus and process or outcome measures were significant. Although not statistically significant among children, the OR for mesalamine use was 0.64, suggesting a similar association as that seen among adults
Time to first dispensing of a biologic therapy in (A) children and (B) adults

My take: This study indicates significant treatment disparities between IBD-focused care providers and providers without an IBD focus in the care for adults, but not in the care of children. This could be related to improved collaboration among pediatric care providers, better training, and parental involvement.

In addition, this study focused on patients with newly-diagnosed disease. Treatment is more complicated in patients who have not responded to initial treatments; as such, IBD-focused providers may be more important in this population.

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Mechanical Dilation vs. Medical Therapy for Pediatric Eosinophilic Esophagitis

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D Burnett et al. JPGN Reports. 2025;6:19–26. A Canadian multicenter pediatric eosinophilic esophagitis cohort: Evidence for a nondilation approach to esophageal narrowing

This was a retrospective study from Vancouver with 332 new diagnosis of eosinophilic esophagitis (EoE).

Key findings:

  • The incidence of EoE in patients less than 15 years old was 5.4 per 100,000 person‐years
  • Of the 332 new diagnoses, 40 (12.0%) had endoscopically-identified esophageal narrowing at diagnosis
  • During follow-up of 1-4 years, 11 (27.5% of narrowed cohort) patients underwent mechanical esophageal dilation
  • “Our most surprising result was the high number of cases of esophageal narrowing that resolved on follow‐up scope after initiating medical/dietary therapy, without need for mechanical dilation.” The rates of resolution were 1 with 1 (100%) on systemic steroids, 7 out of 13 (54%) with topical steroids, 3 out of 4 (75%) with dietary therapy, and 4 out of 12 (33%) with PPI therapy

My take: This study was a little confusing in how the results are presented. Through most of the article, there are 40 (of 332) children with newly-diagnosed EoE who had narrowing identified. However, there is also discussion of a 65 children subset who had follow-up endoscopy and this is the group in which esophageal narrowing treatment response is reported.

Despite the confusion, the clear take-home message is that esophageal narrowing often responds to medical treatment; only a subset of children with esophageal strictures need mechanical dilatation.

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I love walking around NYC -even when it is cold (pictures from February)

Do Setons Improve Outcomes in Anti-TNF Treatment for Fistulas?

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J McCurdy et al. AP&T 2025; https://doi.org/10.1111/apt.70081. The Impact of Setons on Perianal Fistula Outcomes in Patients With Crohn’s Disease Treated With Anti-TNF Therapy: A Multicentre Study

This study included 221 patients — 81 with setons and 140 without setons. Patients were treated with their first anti-TNF therapy for perianal fistulizing Crohn’s disease (PFCD) after undergoing a pelvic MRI between 2005 and 2022 from 6 North American centers. Our primary outcome was major adverse fistula outcome (MAFO), a composite of repeat local surgical intervention, hospitalization, or fecal diversion for PFCD.

Key findings:

  • Patients with setons had similar rates of MAFO (HR 1.23; 95% CI, 0.68–2.21) and fistula remission at 6 months (OR, 0.81; 95% CI, 0.41–1.59) and 12 months (OR, 0.63; 95% CI, 0.31–1.27) compared to patients without setons
  • In patients with abscesses, there were lower rates of MAFO (HR, 0.49; 95% CI, 0.19–1.25) but not statistically significant in patients with setons

My take: This study indicates that seton placement may not be needed in patients who are starting anti-TNF therapy with fistulizing disease, especially if there is not an abscess present.

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Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Essential Learning Objectives in Pediatric Gastroenterology (and All Subspecialties) for Pediatricians and in Pediatric Residency Training

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T Aye et al. J Pediatr 2025; 277, 114380. (Open Access!) Subspecialty Perspectives on the Education Needs for Pediatrics Residency Training

Background: The Council of Pediatric Subspecialties (CoPS) created a list of 3 to 5 learning objectives that each subspecialty believes are the most important practical skills for the general pediatrician and recommends be included in general pediatrics, medicine-pediatrics, and other combined residency program curricula… The Subspecialty Perspectives on (pediatrics) Training (SPoT) action team within CoPS asked each subspecialty representative, most of whom were fellowship program directors at the time, in collaboration with their subspecialty colleagues, to provide a list of 3 to 5 practical learning objectives that should be expected of graduating pediatric residents and practicing general pediatricians in the evaluation and management of conditions related to their subspecialty.

Recommendations for Pediatric Gastroenterology:

My take: This article identifies four of the most important areas in pediatric gastroenterology. If I were to add a fifth, given the wide variety of problems in our field, it would be to know how to quickly reach out to a pediatric gastroenterologist when you need advice.

This article is worth a quick look to see if you have the essential knowledge in all pediatric subspecialty fields (Table 1). One of the most important that relates to pediatric gastroenterology is in the allergy section: “Identify the importance of avoiding indiscriminate testing for food allergy without an appropriate clinical history concerning for IgE mediated food allergy.”

Lifetime Health Effects and Cost-Effectiveness of Tirzepatide and Semaglutide in US Adults

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JH Hwang et al. JAMA Health Forum. 2025;6(3):e245586. Open Access! Lifetime Health Effects and Cost-Effectiveness of Tirzepatide and Semaglutide in US Adults

Methods: The authors modeled the effects of four medications,  tirzepatide and semaglutide compared to phentermine-topiramate and naltrexone-bupropion. The study used data from the 2017-2020 National Health and Nutrition Examination Survey. This included 4823 individuals (representing 126 million eligible US adults) aged 20 to 79 years who would meet the following clinical trial inclusion criteria for these drugs: (1) had a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 30 or greater or (2) had a BMI between 27 and 29.9 and at least 1 weight-related comorbidity (ie, diabetes, hypertension, dyslipidemia, or cardiovascular disease).

Key results:

  • Based on this model, in US adults, over a lifetime, tirzepatide would avert 45,609 obesity cases per 100,000 individuals and and semaglutide would avert 32,087 cases per 100,000 individuals.
  • Tirzepatide and Semaglutide would avert cases of diabetes by 20,854 per 100,000 individuals and 19,211 cases per 100,000 individuals respectively.
  • Tirzepatide and Semaglutide would avert cardiovascular disease cases by 10,655 per 100,000 individuals and 8,263 cases per 100,000 individuals respectively.
  • Despite the largest incremental QALY gains of 0.35 for tirzepatide and 0.25 for semaglutide among all antiobesity medications, the incremental cost-effectiveness ratios were $197,023/QALY and 467,676/QALY, respectively.
  • To reach the $100,000/QALY threshold, their prices would require additional discounts by 30.5% for tirzepatide and 81.9% for semaglutide from their current net prices.

In short, the authors indicate that based on a typical QALY threshold for cost-effectiveness, tirzepatide would need to be priced at $4,334 per year, from the current average of $6,236 per year; semaglutide would need to be $1,522 per year, from an average of about $8,412 per year today.

My take: The costs of these drugs in non-US markets would meet the QALY threshold for cost-effectiveness. However, until the patent on these drugs expires, US consumers are likely to be spending a great deal more. The U.S. patent on semaglutide will expire in 2032, and the U.S. patent on tirzepatide will expire in 2036.

CNN 9/24/24 ‘Greed, greed, greed’: Sanders demands Ozempic maker lower prices: “He {Bernie Sanders] noted that the list price for a four-week supply of Ozempic is $969 in America, but the drug can be purchased for $155 in Canada, $122 in Denmark and $59 in Germany. Similarly, Wegovy’s list price is $1,349 in the US, but it costs $186 in Denmark, $140 in Germany and $92 in the United Kingdom.”

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If you were born on a Tuesday (like me), this is your buddha pose (from Temple of Big Buddha in Bangkok)