Table 1. Comparison of the BSG, CAG, WGO, and AGA Diagnosis, Diet, Treatment, and Other Recommendations.

AGA: American Gastroenterology Association; anti-TNF: anti-tumor necrosis factor; BSG: British Society of Gastroenterology; CAG: Canadian Association of Gastroenterology; WGO: World Gastroenterology Organization; 5-ASA: 5-aminosalicylic acid

Category	BSG	CAG	WGO	AGA
Diagnosis	Recommends ileocolonoscopy, including segmental colonic and ileal biopsies, if small bowel disease is suspected; follow-up with CT enterography.	Recommends endoscopy and biopsy, using the Crohn’s Disease Activity Index (CDAI) as a predictor	Recommends colonoscopy and sigmoidoscopy for the diagnosis using the Mayo endoscopic score and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) score	Recommends endoscopic evaluation. Special emphasis on pathology evaluation.
Location and behavior	Used the Montreal classification	Used the Montreal classification	Used the Montreal classification	Used the Montreal classification
Severity Grading	They recommended that disease severity should be based on a combination of symptoms and objective measures of inflammation. They further recommended using Crohn’s Disease Activity Index (CDAI), the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and the modified Mayo endoscopic score.	They recommended that disease severity should be based on a combination of symptoms and objective measures of inflammation. They further recommended using Crohn’s Disease Activity Index (CDAI), the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and the modified Mayo endoscopic score.	They recommended that disease severity should be based on a combination of symptoms and objective measures of inflammation. They further recommended using Crohn’s Disease Activity Index (CDAI), the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and the modified Mayo endoscopic score.	They recommended that disease severity should be based on a combination of symptoms and objective measures of inflammation. They further recommended using Crohn’s Disease Activity Index (CDAI), the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and the modified Mayo endoscopic score.
Dietary changes	Diet should meet nutritional requirements. Multidisciplinary management with nutritionists. In patients where nutritional requirements cannot be met, enteral or parenteral nutrition is indicated. Patients should be monitored for nutritional parameters, including hemoglobin, proteins, vitamins, and electrolytes.	Recommends against the use of enteral nutrition to prevent remissions, but with a low level of recommendation.	Dietary management with the aid of nutritionists and monitoring to prevent malnourishment. Recommended use of enteral nutrition to prevent remissions.	An anti-inflammatory diet with probiotics and prebiotics, avoid lactose, wheat, and refined sugars; combine vegetables and healthy fats in every meal.
Medical treatment	They recommended 5-ASA. For moderate IBD, they recommended 5-ASA orally, with the addition of 5-ASA enemas. They also recommended corticosteroids used in low to moderate cases only when 5-ASA induction therapy fails. Furthermore, corticosteroids can be used orally or topically. In patients where 5-ASA and corticosteroids failed, treatment escalation with thiopurine, anti-TNF therapy, vedolizumab, or tofacitinib was recommended.	They recommended 5-ASA for any IBD severity and using oral 5-ASA to induce or maintain complete remission. Also, they recommended corticosteroids use from the beginning as first-line therapy. Corticosteroids can also be used orally or topically. In patients where 5-ASA and corticosteroids failed, they recommended that treatment can be escalated with thiopurine, anti-TNF therapy, vedolizumab, or tofacitinib.	They recommended 5-ASA orally, combined with rectal and/or topical treatment. They also recommended corticosteroids use in low to moderate cases only when 5-ASA induction therapy fails. Corticosteroids can also be used orally or topically. In patients where 5-ASA and corticosteroids failed, treatment can be escalated with thiopurine, anti-TNF therapy, vedolizumab, or tofacitinib.	They recommended 5-ASA orally, combined with rectal and/or topical treatment. They also recommended corticosteroid use in low to moderate cases only when 5-ASA induction therapy fails. Corticosteroids can be used orally or topically. In patients where 5-ASA and corticosteroids failed, treatment can be escalated with thiopurine, anti-TNF therapy, vedolizumab, or tofacitinib.
Surgical treatment	In patients that have become medically resistant, have intolerable side effects, or have life-threatening conditions.	In patients that have become medically resistant, have intolerable side effects, or have life-threatening conditions.	In patients that have become medically resistant, have intolerable side effects, or have life-threatening conditions.	In patients that have become medically resistant, have intolerable side effects, or have life-threatening conditions.
Alternative treatment	Fecal microbial transplantation, probiotics, prebiotics, and marijuana	None	Fecal microbial transplantation, probiotics, prebiotics, and marijuana	None