Unauthentic Information About Celiac Disease on Social Networking Pages: Is It a Matter of Concern in Celiac Disease Management?

BACKGROUND: Facebook (FB) is the most popular online networking platform. Many celiac disease Facebook (CD-FB) pages spread awareness about celiac disease (CD). To get the latest information, patients with CD frequently follow such pages. However, little is known about whether such pages provide authentic and reliable information. AIMS: This study aims to investigate whether CD-FB pages spread misleading information to patients with CD. METHODS: On the Facebook social networking platform, CD-FB pages created in three celiac-prevalent countries (Italy, the USA, and India) were explored using different combinations of keywords. The type/category of the CD-FB page, country of origin, purpose, page web link, and number of followers/members were documented in a Microsoft spreadsheet. All posts distributed on selected CD-FB pages in the last 3 years were thoroughly screened. RESULTS: From August 2022 to March 2023, a total of 200 CD-FB pages from Italy, the USA, and India were explored. Out of these 200 pages, 155 CD-FB (Italy 70; the USA 46; India 39) were found eligible. Of them, 20 (13%) CD-FB pages (Italy 4; the USA 5; India 11) shared misleading information about CD. Surprisingly, 11 (8%) of these 20 pages (Italy 0; the USA 2; India 9) supported alternative treatment options for CD. CONCLUSIONS: CD-FB pages are useful for disseminating celiac-disease-related information. While most such pages provide useful information, 13% of CD-FB pages allow misleading information. Patients with CD should consult their treating unit before following any uncertain information posted on CD-FB pages.

The use of urine peptidomics to define dietary gluten peptides from patients with celiac disease and the clinical relevance.

INTRODUCTION: Determination of urinary gluten immunogenic peptides (GIP) has emerged as one of the most attractive test to monitor the adherence to the gluten-free diet (GFD) of patients with celiac disease (CD), being a simple, noninvasive and direct method to detect gluten contamination of the GFD. AREAS COVERED: We conducted a scoping review in Medline (PubMed) of articles published up to April 2023 that analyzed any aspect of the clinical relevance of the use of urinary GIP measurement in patients with CD. A total of 17 articles reporting the clinical use of urinary peptidomics for the follow-up of CD patients were finally included. EXPERT OPINION: Available data suggest that a negative urinary GIP result is a reliable noninvasive predictor of intestinal mucosa healing in CD patients treated with the GFD, especially if testing three urine samples on different days including the weekend. Due to conflicting results about the sensitivity and the specificity of the urinary GIP determination, additional in-depth information is needed, particularly related to (1) the relationship between the amount of ingested gluten and the quantity of urinary GIP excreted in treated CD patients, (2) the GIP kinetics and best timing for sample collection.

Nonceliac gluten sensitivity.

PURPOSE OF REVIEW: To describe recent advances on nonceliac gluten sensitivity (NCGS), a recently described disorder characterized by variable symptoms and frequent irritable bowel syndrome (IBS)-like manifestations. RECENT FINDINGS: The recent description of disease-triggering wheat components other than gluten, such as fructans and amylase-trypsin inhibitors (ATIs), definitely suggests that nonceliac wheat sensitivity (NCWS) is a better 'umbrella' terminology than NCGS. Self-reported NCWS is very common worldwide, particularly in patients seen at the gastroenterology clinic, but many of these diagnoses are not confirmed by standard clinical criteria. A biomarker of NCWS is still lacking, however, subtle histological features at the small intestinal biopsy may facilitate diagnosis. Treatment of NCWS is based on the gluten-free diet (GFD). The GFD has proven to be an effective treatment of a significant proportion of NCWS-related IBS patients. Dietary therapies for IBS, including the GFD, should be offered by dietitians who first assess dietary triggers and then tailor the intervention according to patient choice. Pioneer studies are under way to test the therapeutic efficacy of supplemental gluten-digesting enzyme preparations in patients with NCWS. SUMMARY: Recent studies highlight interesting pathophysiological and clinical features of NCWS. Many questions remain, however, unanswered, such as the epidemiology, a biomarker(s), and the natural history of this clinical entity.

Lower Level of Plasma 25-Hydroxyvitamin D in Children at Diagnosis of Celiac Disease Compared with Healthy Subjects: A Case-Control Study.

OBJECTIVE: To evaluate the vitamin D status of children with a new diagnosis of celiac disease compared with healthy controls. STUDY DESIGN: This was a case-control study. Cases were consecutive children with newly diagnosed celiac disease. Controls were healthy children matched for age, sex, ethnicity, and month of blood testing. Plasma 25-hydroxyvitamin D (25-OHD) was measured as the index of vitamin D nutritional status. The Student t test was used for comparisons. Differences in frequencies were evaluated with the χ2 test. Associations between variables were estimated by calculating Pearson correlation coefficients. RESULTS: There were 131 children with celiac disease enrolled (62% females; mean age 8.1 ± 1.1 years). The control group included 131 healthy children (62% females; mean age 8.2 ± 1.2). All were of European origin. Plasma 25-OHD levels were significantly lower in patients than in controls (25.3 ± 8.0 and 31.6 ± 13.7 ng/mL; P < .0001). The percentage of children with vitamin D deficiency (<20 ng/mL) was significantly higher in children with celiac diseaseas compared with controls (31% vs 12%; P < .0001). The concentration of 25-OHD was significantly lower in patients than in controls during summer (P < .01) and autumn (P < .0001). CONCLUSIONS: In this case-control study, at diagnosis, children with celiac disease showed lower levels of plasma 25-OHD compared with healthy subjects. Vitamin D status should be checked at diagnosis of celiac disease, particularly during summer and fall months.

Is Fecal Calprotectin a Useful Marker for Small Bowel Crohn Disease?

OBJECTIVES: The identification of reliable non-invasive biomarkers of Crohn disease (CD) activity is crucial. Fecal calprotectin (FC) is the most promising one. We aimed to define whether its performance for isolated ileal CD could be as useful as for colonic and ileocolonic disease. METHODS: Retrospective observational study of all pediatric patients affected with CD with FC and inflammatory blood markers performed within one week from an ileocolonoscopy or magnetic resonance enterography. The sensitivity, specificity, negative predictive value, positive predictive value and accuracy of FC >50 mcg/g were evaluated for isolated ileal CD (L1), colonic CD (L2) and ilecolonic CD (L3) using ilecolonoscopy and magnetic resonance enterography as the reference standard. The best FC cut-off for each disease location was evaluated using receiver operating characteristic curves. RESULTS: One-hundred seventy-six FC measurements from a total of 98 patients were collected (14.3% L1, 10.2% L2, 75.5% L3). The sensitivity and specificity of FC for L1 CD were 36% and 91%, respectively, compared to 93% and 75% for L2 and 70% and 95% for L3. An FC of 95 mg/kg was identified as the best cut off for identification of active isolated ileal disease, with a sensitivity of 77% and a specificity of 56% [area under the curve (confidence interval [CI] 0.56- 0.97) 0.77, P = 0.02]. CONCLUSIONS: With a sensitivity of 36%, FC alone does not accurately reflect isolated L1 disease activity. A significantly lower threshold should be applied for increasing its performance for isolated small bowel CD monitoring.

Safety of Biological Therapy in Children With Inflammatory Bowel Disease.

OBJECTIVES: Retrospective, observational, single-center, cohort study investigating the safety profile of biological therapy in children with inflammatory bowel disease (IBD). METHODS: Retrospective, observational, cohort study of pediatric patients with IBD, receiving infliximab, adalimumab, vedolizumab, or ustekinumab for at least 2 months. Data related to the immediate and delayed adverse events (AEs) were collected, focusing on the reaction type and severity, the time of onset, the outcome and the temporary or definitive therapy discontinuation secondary to the AE. Number of suspected and confirmed coronavirus disease-209 (COVID-19) cases and their outcomes, as well as flu vaccination coverage were collected. RESULTS: One hundred eighty-five children were included (101 [55%] CD, 82 [44%] UC, and 2 [1%] IBDU): 149 received infliximab (IFX) (81%), 88 (48%) adalimumab (ADA), 18 (21%) vedolizumab, and 4 (2%) ustekinumab. The overall AE rates were 49%, 67% of whom likely medication-related. Eleven (6%) patients experienced more than 1 AE, 18 patients (10%) presented an immediate reaction, and 82 (45%) a delayed AE. Among the 90 patients experiencing at least 1 AE, 97% had mild-to-moderate AEs. Only 4 SAEs were reported (4%). Treatment discontinuation because of AE occurred in 25 patients (14%). Four COVID-19 cases were reported, all with a mild course. CONCLUSIONS: Our findings confirm a good safety profile of biologics. Infusion reactions to IFX administration remain one of the main issues, significantly linked to its immunogenicity and consequently with an impact on its efficacy and durability.

Contribution of Oral Hygiene and Cosmetics on Contamination of Gluten-free Diet: Do Celiac Customers Need to Worry About?

OBJECTIVES: The only available treatment for celiac disease (CD) is the gluten-free diet. It is unclear whether the presence of gluten in oral hygiene products and cosmetics that are applied on the mouth is a reason of concern for CD patients. The aim of this study was to test the level of gluten contamination in oral hygiene and cosmetic products available in the Italian market. METHODS: A total of 66 products (toothpastes = 37; dental tablets = 2; mouthwashes = 5; lip-balms = 10; lipsticks = 12) labelled gluten-free or with unknown gluten content were randomly collected from different supermarkets and pharmacies. The gluten quantification was determined by the R5 ELISA method approved by EU regulations. RESULTS: Out of 66 oral hygiene and cosmetics, 62 products (94%) were found to be gluten-free (gluten level <20 ppm), while 4 (6%) (toothpastes = 3; lipsticks = 1) showed a gluten level >20 ppm (toothpastes: 20.7, 31.4, and 35 ppm; lipstick: 27.4 ppm). None of the selected products had ingredient derived from wheat, barley, or rye. CONCLUSIONS: Gluten contamination is currently not an issue in a wide array of cosmetic and oral hygiene products that are commonly in the market.

The Role of Diet and Nutritional Interventions for the Infant Gut Microbiome.

The infant gut microbiome plays a key role in the healthy development of the human organism and appears to be influenced by dietary practices through multiple pathways. First, maternal diet during pregnancy and infant nutrition significantly influence the infant gut microbiota. Moreover, breastfeeding fosters the proliferation of beneficial bacteria, while formula feeding increases microbial diversity. The timing of introducing solid foods also influences gut microbiota composition. In preterm infants the gut microbiota development is influenced by multiple factors, including the time since birth and the intake of breast milk, and interventions such as probiotics and prebiotics supplementation show promising results in reducing morbidity and mortality in this population. These findings underscore the need for future research to understand the long-term health impacts of these interventions and for further strategies to enrich the gut microbiome of formula-fed and preterm infants.

Performance assessment of a new G12/A1 antibody-based rapid ELISA using commercially available and gluten-spiked food samples.

OBJECTIVE: Food products with <20 mg/kg gluten can be labeled 'gluten-free' according to international regulations. Several antibodies-based ELISAs have been develop to track gluten traces in food products. Among them, R5 and G12 antibody-based ELISAs are the frequently used methods. However, these antibodies have certain limitations. We evaluated the accuracy of G12/A1 antibody-based 'Glutentox ELISA Rapid G12' and compared the results with the current reference method i.e., R5 antibody-based 'Ridascreen R5 ELISA'. METHODS: In the first step, the performance of Glutentox ELISA Rapid G12 kit was inspected by determination of the threshold value i.e., > or <20 mg/kg gluten in different food products. In the second step, quantification accuracy was assessed by quantification of gluten in gluten-free food products spiked with gliadin reference material. RESULTS: In total 47 food products (naturally and labeled gluten-free, and food with traces of gluten) were included. Of them, 29 products were quantified with <20 mg/kg, and 18 with a low level of gluten by both the kits. Six out of 29 gluten-free products were used for the recovery test at different spike levels. Gluten concentration and mean recovery rates of individual kits showed consistency. CONCLUSION: GlutenTox Rapid G12 ELISA could be an appropriate choice for detecting gluten in food products but needs more in-house validation and collaborative tests.

Histologic findings at diagnosis as predictive markers of clinical outcome in pediatric ulcerative colitis.

BACKGROUND: The role of histological inflammation at diagnosis as a possible prognostic factor for disease course has not been investigated. AIMS: To assess whether histologic findings at diagnosis could predict clinical outcomes and evaluate the association between clinical, biochemical, endoscopic, and histological findings. METHODS: Prospective single-center study including pediatric UC patients with a minimum follow-up of 12 months. The association between histological activity (Nancy Index, Robarts Histopathology Index, and Geboes Score) and 12-month clinical outcomes was evaluated. Secondarily, we assessed the correlation between histological scores and endoscopic and inflammatory markers at the diagnosis. Inter-observer agreement for histologic and endoscopic scores was also evaluated. RESULTS: Forty-nine UC patients were included. No association was found between 1-year clinical relapse and the three histological indices at diagnosis (p > 0.05). Good concordance was found among the three histological scores (p < 0.001), and between all histological and endoscopic indices (p < 0.05). No correlation was found between histologic scores and serum inflammatory markers. Inter-observer agreement was good for eMayo, Nancy and Robarts score (k = 0.71, k = 0.74 and k = 0.68, respectively) and moderate for Geboes (k = 0.46). CONCLUSIONS: Histological findings at diagnosis cannot be used as a predictor of the disease course. The three histological scores used in routine clinical practice show an overall good correlation and reliability.

Vitamin D status in healthy Italian school-age children: a single-center cross-sectional study.

BACKGROUND: Vitamin D is involved in calcium homeostasis and bone metabolism, although its extra-skeletal actions are also well-known. Low serum 25(OH)D levels are common both in adults and children worldwide. METHODS: The purpose of this cross-sectional study was to determine the distribution of 25(OH)D levels in a cohort of healthy Italian school-age children, aged 5-10 years, in relationship to determinants of vitamin D deficiency such as season, BMI, gender, age and ethnicity. RESULTS: The mean serum 25(OH) D level was 28.2 ng/mL; the prevalence of 25(OH)D sufficiency (> 30 ng/mL), insufficiency (20-30 ng/mL), deficiency (10-20 ng/mL) and severe deficiency (< 10 ng/mL) was 36%, 37%, 21% and 6% of the study-group population, respectively. The lower serum 25(OH)D values were observed during winter (21.6 ng/mL) and spring (22.9 ng/mL), as compared to summer (46.7 ng/mL) (p < 0.001). Higher BMI z-scores were associated with lower 25(OH)D level while no statistical difference was observed as related to gender and age groups. CONCLUSIONS: Healthy Italian schoolchildren show low 25(OH)D levels, particularly during winter and spring time. Seasonality, ethnicity and overweight/obesity were confirmed to influence the vitamin D status, thus indicating the need for effective initiatives to support adequate vitamin D status in this population group.

Effects of the supplementation with a multispecies probiotic on clinical and laboratory recovery of children with newly diagnosed celiac disease: A randomized, placebo-controlled trial.

OBJECTIVE: To evaluate the efficacy of a multispecies probiotic on clinical and laboratory recovery of children with celiac disease (CeD) at diagnosis. METHODS: Children with newly diagnosed CeD entered a randomized double-blind placebo-controlled trial. A gluten-free diet (GFD) plus a multispecies probiotic or placebo were administered for 12 weeks. Growth, laboratory, and clinical parameters were recorded at enrollment, after 3 and 6 months of follow-up. RESULTS: Overall, 96 children completed the study: 49 in group A (placebo) and 47 in group B (probiotic). A significant increase of BMI-Z score was found in both groups after 3 and 6 months of treatment (p < 0.001), however the increase of BMI-Z score was significantly higher and faster in Group B than in Group A. Other clinical and laboratory parameters improved in both groups after 3 and 6 months (p<0.001), but no difference was found between the groups and a comparable time trend was observed in both groups. CONCLUSIONS: Treatment with a multispecies probiotic induced a higher and faster increase of BMI in children with newly diagnosed CeD. The mechanism of this positive effect remains to be elucidated.

Prevalence and detection rate of celiac disease in Italy: Results of a SIGENP multicenter screening in school-age children.

BACKGROUND: Celiac disease is a common lifelong disorder. Recent studies indicate that the number of clinically detected cases has increased over the last decades, however little is known about changes in the prevalence and the detection rate of celiac disease. AIM: To evaluate the current prevalence and detection rate of celiac disease in Italy by a multicenter, mass screening study on a large sample of school-age children. METHODS: children aged 5-11 years were screened at school by HLA-DQ2 and -DQ8 determination on a drop of blood in six Italian cities; total serum IgA and IgA anti-transglutaminase were determined in children showing HLA-DQ2 and/or -DQ8 positivity. Diagnosis of celiac disease was confirmed according to the European guidelines. RESULTS: 5994 children were eligible, 4438 participated and 1873 showed predisposing haplotypes (42.2%, 95% CI=40.7-43.7). The overall prevalence of celiac disease was 1.65% (95% CI, 1.34%-2.01%). Only 40% of celiac children had been diagnosed prior to the school screening. Symptoms evoking celiac disease were as common in celiac children as in controls. CONCLUSION: In this multicenter study the prevalence of celiac disease in school-age Italian children was one of the highest in the world. Determination of HLA predisposing genotypes is an easy and fast first-level screening test for celiac disease. Without a mass screening strategy, 60% of celiac patients remain currently undiagnosed in Italy.

Outcome of Very Early Onset Inflammatory Bowel Disease Associated With Primary Sclerosing Cholangitis: A Multicenter Study From the Pediatric IBD Porto Group of ESPGHAN.

BACKGROUND: Whether primary sclerosing cholangitis related to inflammatory bowel disease (PSC-IBD) diagnosed before 6 years (ie, VEO-IBD) has a distinct phenotype and disease course is uninvestigated. We aimed to analyze the characteristics and natural history of VEO-PSC-IBD, compared with early and adolescent-onset PSC-IBD. METHODS: This is a multicenter, retrospective, case-control study from 15 centers affiliated with the Porto and Interest IBD group of ESPGHAN. Demographic, clinical, laboratory, endoscopic, and imaging data were collected at baseline and every 6 months. Inflammatory bowel disease-related (clinical remission, need for systemic steroids and biologics, and surgery) and PSC-related (biliary and portal hypertensive complications, need for treatment escalation and liver transplantation, cholangiocarcinoma, or death) outcomes were compared between the 2 groups. RESULTS: Sixty-nine children were included, with a median follow-up of 3.63 years (interquartile range, 1-11): 28 with VEO-PSC-IBD (23 UC [82%], 2 IBD-U [7%] and 3 [11%] CD), and 41 with PSC-IBD (37 UC [90%], 3 IBDU [7.5%] and 1 [2.5%] CD). Most patients with UC presented with pancolitis (92% in VEO-PSC-UC vs 85% in PSC-UC, P = .2). A higher number of patients with VEO-PSC-IBD were diagnosed with PSC/autoimmune hepatitis overlap syndrome than older children (24 [92%] vs 27 [67.5%] PSC-IBD, P = .03), whereas no other differences were found for PSC-related variables. Time to biliary strictures and infective cholangitis was lower in the VEO-PSC-IBD group (P = .01 and P = .04, respectively), while no difference was found for other outcomes. No cases of cholangiocarcinoma were reported. CONCLUSIONS: Primary sclerosing cholangitis related to inflammatory bowel disease has similar baseline characteristics whether diagnosed as VEO-IBD or thereafter. A milder disease course in terms of biliary complications characterizes VEO-PSC-IBD.

Very early onset primary sclerosing cholangitis associated with IBD (VEO-PSC-IBD) often presents with autoimmune features and shows a milder PSC disease course than later-onset disease. These findings highlight the significance of studying the distinctive genetic and pathophysiological factors specific to VEO disease.

Induction of Remission With Exclusive Enteral Nutrition in Children With Crohn's Disease: Determinants of Higher Adherence and Response.

BACKGROUND: Exclusive enteral nutrition (EEN) is the first choice to induce remission and promote mucosal healing in pediatric Crohn's disease (CD). However, full adherence to EEN treatment may be problematic for children with CD. METHODS: The goal of the current multicenter retrospective study was to define predictive factors of nonadherence to treatment and nonremission at the end of induction treatment. Those data together were analyzed with the ultimate goal of trying to define an individualized induction treatment for children with CD. RESULTS: Three hundred seventy-six children with CD from 14 IBD pediatric referral centers were enrolled in the study. The rate of EEN adherence was 89%. Colonic involvement and fecal calprotectin >600 µg/g at diagnosis were found to be associated with a reduced EEN adherence. Exclusive enteral nutrition administered for 8 weeks was effective for inducing clinical remission in 67% of the total cohort. Factors determining lower remission rates were age >15 years and Pediatric Crohn's Disease Activity Index >50. CONCLUSION: Although EEN is extremely effective in promoting disease remission, several patients' related factors may adversely impact EEN adherence and response. Personalized treatments should be proposed that weigh benefits and risks based on the patient's disease location, phenotype, and disease activity and aim to promote a rapid control of inflammation to reduce long-term bowel damage.

Metabolic Bone Disease in Children with Intestinal Failure and Long-Term Parenteral Nutrition: A Systematic Review.

Metabolic bone disease (MBD) is a possible complication of intestinal failure (IF), with a multi-factorial pathogenesis. The reduction of bone density (BMD) may be radiologically evident before manifestation of clinical signs (bone pain, vertebral compression, and fractures). Diagnosis relies on dual-energy X-ray absorptiometry (DXA). Incidence and evolution of MBD are not homogeneously reported in children. The aim of this systematic review was to define the prevalence of MBD in IF children and to describe risk factors for its development. A comprehensive search of electronic bibliographic databases up to December 2021 was conducted. Randomized controlled trials; observational, cross-sectional, and retrospective studies; and case series published between 1970 and 2021 were included. Twenty observational studies (six case-control) were identified and mostly reported definitions of MBD based on DXA parameters. Although the prevalence and definition of MBD was largely heterogeneous, low BMD was found in up to 45% of IF children and correlated with age, growth failure, and specific IF etiologies. Data demonstrate that long-term follow-up with repeated DXA and calcium balance assessment is warranted in IF children even when PN dependence is resolved. Etiology and outcomes of MBD will be better defined by longitudinal prospective studies focused on prognosis and therapeutic perspectives.

Distribution of celiac disease predisposing genes HLA-DQ2 and HLA-DQ8 in the native population of southern India.

BACKGROUND: Celiac disease (CD) is an intestinal inflammatory condition caused by the ingestion of gluten peptides in wheat and related grains in individuals carrying HLA-DQ2 and/or HLA-DQ8 genes. In comparison to HLA-DQ8, a higher HLA-DQ2 prevalence is reported in European population where wheat has been the staple food for thousands of years. In non-European population, this pattern of HLA-DQ CD-predisposing gene distribution has not always been found. The aim of this study was to evaluate the HLA-DQ2 and HLA-DQ8 distribution in the native low-gluten consuming southern Indian population. METHODS: Overall, 211 dried blood spots (DBS) were collected from native southern Indian individuals. HLA-DQ characterization and the determination of homozygous/heterozygous status were performed using commercially available HLA-DQ typing kits. RESULTS: Of 211 collected DBS, 88 (42%, 95% CI: 36-48) were positive for HLA-DQ2 and/or HLA-DQ8 heterodimers. Overall, 40 (19%, 95% CI: 14-24) samples typed positive for HLA-DQ2 and 48 (23%, 95% CI: 18-28) typed positive for HLA-DQ8 genotypes. Of 40 HLA-DQ2-positive individuals, only one subject tested homozygous for the DQB1*02 allele. CONCLUSIONS: In the southern Indian native general population, the prevalence of HLA-DQ8 is higher in comparison to HLA-DQ2 prevalence. This finding could be related to the delayed introduction of wheat in the diet of the southern Indian population.

The Clinical Spectrum of Inflammatory Bowel Disease Associated With Specific Genetic Syndromes: Two Novel Pediatric Cases and a Systematic Review.

Background and Aims: Inflammatory bowel disease (IBD) is a typical polygenic disorder and less frequently shows a monogenic origin. Furthermore, IBD can originate in the context of specific genetic syndromes associated with a risk of autoimmune disorders. We aimed to systematically evaluate the prevalence of IBD in specific genetic syndromes and to review the clinical characteristics of the published cases. Methods: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, studies describing patients with IBD and a genetic syndrome and/or studies indicating the prevalence or incidence of IBD in subjects with a genetic syndrome were included. Results: Forty-six studies describing a total of 67 cases of IBD in six genetic syndromes and two personally assessed unpublished cases were included in the review. The majority of cases were associated with Turner syndrome (TS) (38 cases), Down syndrome (DS) (18 cases) and neurofibromatosis type 1 (NF1) (8 cases). Sporadic cases were described in DiGeorge syndrome (2), Kabuki syndrome (2), and Williams syndrome (1). The prevalence of IBD ranged from 0.67 to 4% in TS and from 0.2 to 1.57% in DS. The incidence of IBD was increased in TS and DS compared to the general population. Eight cases of IBD in TS had a severe/lethal course, many of which described before the year 2000. Two IBD cases in DS were particularly severe. Conclusion: Evidence of a greater prevalence of IBD is accumulating in TS, DS, and NF1. Management of IBD in patients with these genetic conditions should consider the presence of comorbidities and possible drug toxicities. Systematic Review Registration: PROSPERO, identifier: CRD42021249820.