Guideline sources The following summarized guidelines for the evaluation and management of Crohn's disease (CD) are prepared by our editorial team based on guidelines from the European Society for Clinical Nutrition and Metabolism (ESPEN 2023), the European Society of Gastrointestinal Endoscopy (ESGE 2023), the World Society of Emergency Surgery (WSES/AAST 2021), the American Gastroenterological Association (AGA 2021; 2020; 2018; 2017; 2013), the American College of Gastroenterology (ACG 2021; 2018; 2017), the American College of Radiology (ACR 2021), the American Society of Colon and Rectal Surgeons (ASCRS 2020; 2015), the European Crohn's and Colitis Organisation (ECCO 2020; 2019; 2015), the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN/ECCO 2020), the Canadian Association of Gastroenterologists (CAG 2019), the British Society of Gastroenterology (BSG 2019), the https://web.pathway.md/diseases/recFEepjgYMnE2bAn 1/28 6/23/23, 3:37 AM Crohn's disease Pathway Healthcare Infection Society (HIS/BSG 2018), the Latin American Federation of Nutritional Therapy, Clinical Nutrition and Metabolism (FELANPE/ASPEN 2017), and the Clinical Pharmacogenetics Implementation Consortium (CPIC 2011). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 17 18 19 20 21 22 23 24 25 26 27 27 27 28 Definition CD is a chronic relapsing IBD characterized by a transmural granulomatous inflammation most commonly affecting the ileum, colon, or both. 27 Epidemiology The exact cause of CD is unknown; however, a complex interplay of genetic factors, environmental factors, immune dysregulation to intestinal microbiota have been implicated. 27 Disease course The complex interplay of genetic, environmental factors and immune dysregulation to intestinal microbiota result in CD, which causes clinical manifestations of chronic diarrhea, fatigue, abdominal pain, weight loss, bloody stools, mucinous stools, peripheral arthritis, aphthous stomatitis, uveitis, erythema nodosum, ankylosing spondylitis, pyoderma, gangrenosum, psoriasis, PSC. Disease progression may lead to fistulae and decreased quality of life. 27 Prognosis and risk of recurrence The annual mortality rate in CD is 1.6%. 28 Guidelines 1. Screening and diagnosis Clinical presentation: Recognize that hallmark/cardinal symptoms of CD include abdominal pain, diarrhea, and fatigue; weight loss, fever, growth failure, anemia, recurrent fistulas, or extraintestinal manifestations can also be presenting features. E Recognize that extraintestinal manifestations of CD include: seronegative arthritis (both axial and peripheral) dermatological pathology (including pyoderma gangrenosum and erythema nodosum) ocular pathology (including uveitis, scleritis, and episcleritis) hepatobiliary disease (PSC) thromboembolic complications (both venous and arterial) bone disease (osteoporosis, osteonecrosis) cholelithiasis and nephrolithiasis https://web.pathway.md/diseases/recFEepjgYMnE2bAn 2/28 6/23/23, 3:37 AM Crohn's disease Pathway immune-mediated diseases (asthma, chronic bronchitis, pericarditis, psoriasis, celiac disease, rheumatoid arthritis, and multiple sclerosis). (Summary statement). E Natural history: Recognize that: CD, in most cases, is a chronic, progressive, destructive disease the location of CD tends to be stable, but can occasionally extend most, but not all, patients with CD will present with non-penetrating, non-stricturing disease behavior, but up to half of the patients would have developed an intestinal complication (stricture, abscess, fistula, or phlegmon) within 20 years of diagnosis patients with ileal, ileocolonic, or proximal gastrointestinal involvement are significantly more likely than patients with an isolated colonic disease to progress to an intestinal complication extensive anatomic involvement and deep ulcerations are other risk factors for progression to intestinal complications over long periods of observation, only 20-30% of patients with CD will have a non-progressive or indolent course, therefore, the majority of patients will require active effort to identify therapies that achieve adequate control of bowel inflammation features associated with a high risk for progressive disease burden include young age at diagnosis, initial extensive bowel involvement, ileal/ileocolonic involvement, perianal/severe rectal disease, and patients presenting with a penetrating or stenosis disease phenotype visceral adiposity may be a marker for increased risk of penetrating disease symptoms of CD do not correlate well with the presence of active inflammation perianal fistulizing CD occurs in up to one-quarter of patients symptoms of CD occur in most cases as a chronic, intermittent course; only a minority of patients will have continuously active symptomatic disease or prolonged symptomatic remission in the absence of immunomodulator or biologic treatment, corticosteroid dependency and/or resistance occurs in up to half of patients up to 80% of patients require hospitalization at some point during their clinical course, but the annual hospitalization rate decreases in later years after diagnosis the 10-year cumulative risk of major abdominal surgery in CD is 40-55%, although recent studies performed in the biologic era suggest that the 10-year risk may have decreased to 30%; the 10-year risk of a second resection after the first is 35%, although again more recent studies suggest that this may have dropped to closer to 30% the 5-year rate of symptomatic postoperative recurrence is 50% overall mortality is slightly increased, with a standardized mortality ratio of 1.4 times that of the general population; causes of excess mortality include gastrointestinal disease, gastrointestinal cancer, lung disease, and lung cancer. E Diagnosis: As per WSES 2021 guidelines, diagnose CD based on a set of modalities including clinical, biochemical, endoscopic, radiological, and histological diagnostics rather than a single reference standard. B https://web.pathway.md/diseases/recFEepjgYMnE2bAn 3/28 6/23/23, 3:37 AM Crohn's disease Pathway As per ACG 2018 guidelines, diagnose CD clinically, even though there are no truly pathognomonic features, with the support of endoscopic, radiographic, and histologic criteria with evidence of chronic intestinal inflammation. E 2. Diagnostic investigations Routine blood tests: Obtain laboratory investigations for inflammation, anemia, dehydration, and malnutrition as part of the initial evaluation of patients with CD. E Do not obtain serologic markers of IBD routinely to establish the diagnosis of CD. D Stool tests (fecal calprotectin): obtain fecal calprotectin to help differentiate the presence of IBD from IBS. B Stool tests, fecal pathogens: As per ACG 2021 guidelines, obtain stool testing for C. difficile infection in patients with IBD presenting with an acute flare associated with diarrhea. B As per ACG 2018 guidelines, obtain stool testing for fecal pathogens and C. difficile in patients with symptoms of active CD. E As per AGA 2017 guidelines, obtain stool testing for C. difficile infection in patients presenting with a flare of underlying IBD. B Emergency laboratory workup: Obtain the following laboratory tests, if possible, for the assessment of disease activity in patients with CD in urgent clinical situations: CBC, including Hgb, WBC count, and platelet count inflammatory markers, including serum CRP and ESR serum electrolytes liver enzymes serum albumin renal function tests blood workup for infectious causes. B Show 4 more Genetic testing: do not obtain genetic testing to establish the diagnosis of CD, albeit certain genetic variants are associated with different phenotypic expressions. D Diagnostic imaging, general approach: As per ESGE 2023 guidelines, obtain dedicated cross-sectional imaging for small-bowel evaluation to assess the extent and location of any CD lesions, to identify strictures, and to assess for extraluminal disease in patients with established CD based on ileocolonoscopy findings. A As per ACG 2018 guidelines, obtain small bowel imaging as part of the initial diagnostic workup in patients with suspected CD. E https://web.pathway.md/diseases/recFEepjgYMnE2bAn 4/28 6/23/23, 3:37 AM Crohn's disease Pathway Show 2 more As per AGA 2018 guidelines, obtain cross-sectional enterography at diagnosis of CD to detect small bowel inflammation and penetrating complications beyond the reach of standard ileocolonoscopy. A Show 6 more Diagnostic imaging, perianal disease: As per ACR 2021 guidelines, obtain any of the following modalities as the initial imaging of suspected proctitis or pouchitis: MR enterography CT enterography pelvic MRI without and with IV contrast pelvic CT with IV contrast. B As per CAG 2019 guidelines, obtain imaging MRI or EUS (based on availability and local expertise) in patients with CD and signs and/or symptoms of active fistulizing disease, to delineate the anatomy of the fistula tracts. B As per ACG 2018 guidelines, consider obtaining cross-sectional imaging with MRI of the pelvis and/or EUS to further characterize perianal CD and perirectal abscesses. E As per AGA 2018 guidelines, obtain dedicated pelvic MRI (perianal fistula MRI protocol) for the adequate preoperative assessment of perianal CD and its complications (number of fistula tracts, location and relationship to anal sphincter muscle complex, and presence of abscess). A Diagnostic imaging, complications: As per ESGE 2023 guidelines, obtain dedicated small-bowel cross-sectional imaging in patients with suspected CD and obstructive symptoms or known bowel stenosis. B As per AAST/WSES 2021 guidelines, obtain IV contrast-enhanced CT in the emergency setting in patients with IBD presenting with acute abdomen, to exclude intestinal perforation, stenosis, bleeding, and abscesses and to help guide decision-making for immediate surgery or initial conservative management. B Show 5 more As per ACG 2018 guidelines, obtain cross-sectional imaging of the abdomen and pelvis if an intra-abdominal abscess is suspected. E Evaluation of anemia: obtain anemia workup (including at least RBC indices such as red cell distribution width and MCV, reticulocyte count, differential blood cell count, serum ferritin, transferrin saturation, and CRP concentration) if the Hgb is below normal. Include the following in a more extensive workup: serum concentrations of vitamin B12, folic acid, haptoglobin, the percentage of hypochromic red cells, reticulocyte Hgb, LDH, soluble transferrin receptor, creatinine, and urea. B Show 8 more Screening for osteoporosis: https://web.pathway.md/diseases/recFEepjgYMnE2bAn 5/28 6/23/23, 3:37 AM Crohn's disease Pathway As per ESPEN 2023 guidelines, monitor serum 25-hydroxyvitamin D status in adult and pediatric patients with active IBD on corticosteroid treatment or suspected vitamin D deficiency. Initiate calcium/vitamin D supplementation, if required, to prevent low bone mineral density. Manage osteopenia and osteoporosis according to current osteoporosis guidelines. B As per ACG 2017 guidelines, screen for osteoporosis with bone mineral density testing at the time of diagnosis and periodically after diagnosis in patients with CD and conventional risk factors for abnormal bone mineral density. B Screening for depression and anxiety: Screen patients with IBD for depression and anxiety. B Assess and manage stress, depression, and anxiety as part of the comprehensive care of patients with CD. B 3. Diagnostic procedures Lower gastrointestinal endoscopy and biopsy: As per ESGE 2023 guidelines: Perform ileocolonoscopy as the first endoscopic examination in patients with suspected CD. A Perform device-assisted enteroscopy with small-bowel biopsies in patients with noncontributory ileocolonoscopy and suspected CD on small-bowel cross-sectional imaging or small-bowel capsule endoscopy. A As per WSES 2021 guidelines, perform sigmoidoscopy in an acute setting, if available, for intra- luminal assessment of distal disease activity, bleeding source identification, and biopsies. B As per ASCRS 2020 guidelines, perform biopsies of suspicious lesions (such as mass, ulcer) identified in patients with CD, especially when considering small bowel or colonic strictureplasty. B As per ACG 2018 guidelines, perform lower gastrointestinal endoscopy (ileocolonoscopy) with biopsies for the assessment of patients with suspected CD. E Show 2 more Upper gastrointestinal endoscopy: Perform upper gastrointestinal endoscopy only in patients with upper gastrointestinal signs and symptoms. E Consider performing deep enteroscopy to provide additional information in patients with suspected CD requiring biopsy/sampling of small bowel tissue to make a diagnosis. E Video capsule endoscopy, indications: As per ESGE 2023 guidelines, perform small bowel capsule endoscopy as the initial diagnostic modality for investigating the small bowel, in the absence of obstructive symptoms or known bowel stenosis, in patients with suspected CD and negative ileocolonoscopy findings. A Show 2 more https://web.pathway.md/diseases/recFEepjgYMnE2bAn 6/28 6/23/23, 3:37 AM Crohn's disease Pathway As per ACG 2018 guidelines, consider performing video capsule endoscopy as an adjunct in the diagnosis of small bowel CD in patients with a high index of suspicion of small bowel disease. E Video capsule endoscopy, preparation: As per ESGE 2023 guidelines, administer a patency capsule before small bowel capsule endoscopy to decrease the capsule retention rate in patients with suspected CD and obstructive symptoms B and in patients with established CD. B Show 2 more As per ACG 2018 guidelines, obtain small bowel imaging and/or patency capsule evaluation before video capsule endoscopy in patients with obstructive symptoms, in order to decrease the risk of capsule retention. E Video capsule endoscopy (capsule retention): offer initial conservative treatment in case of capsule retention. Perform device-assisted enteroscopy if medical therapy fails to achieve spontaneous capsule passage. A 4. Medical management Induction of remission, mild-to-moderate disease, 5-ASAs: As per ECCO 2020 guidelines, avoid using 5-aminosalicylic acid for induction of remission in patients with CD. D As per ACG 2018 guidelines: Consider initiating sulfasalazine for the treatment of patients with mild-to-moderately active colonic CD. C Do not use oral mesalamine for induction of remission and achieving mucosal healing in patients with active CD. D Induction of remission, mild-to-moderate disease, corticosteroids: As per ECCO 2020 guidelines, initiate budesonide for induction of clinical remission in patients with active mild-to-moderate CD limited to the ileum and/or ascending colon. B As per ACG 2018 guidelines, administer controlled ileal release budesonide at a dose of 9 mg once daily for induction of symptomatic remission in patients with mild-to-moderate ileocecal CD. B Induction of remission, mild-to-moderate disease, antibiotics: As per ESPEN 2023 guidelines, insufficient evidence to recommend an antibiotic regimen for the management of active CD. I As per ACG 2018 guidelines: Do not use metronidazole D or ciprofloxacin as primary therapy for induction of remission in patients with luminal inflammatory CD. D Do not use antimycobacterial agents as primary therapy for induction of remission or mucosal healing in patients with CD. D https://web.pathway.md/diseases/recFEepjgYMnE2bAn 7/28 6/23/23, 3:37 AM Crohn's disease Pathway Induction of remission, moderate-to-severe disease (5-ASAs): do not use 5-ASA or sulfasalazine for induction of remission in adult outpatients with moderate-to-severe CD. D Induction of remission, moderate-to-severe disease, corticosteroids: As per AGA 2021 guidelines, consider initiating corticosteroids for induction of remission in adult outpatients with moderate-to-severe CD. C As per ECCO 2020 guidelines, consider initiating systemic corticosteroids for induction of clinical response and remission in patients with active moderate-to-severe CD. C As per ACG 2018 guidelines, initiate a short-term course of oral corticosteroids to alleviate signs and symptoms in patients with moderate-to-severely active CD. B Show 2 more Induction of remission, moderate-to-severe disease, other immunosuppressants: As per AGA 2021 guidelines: Consider initiating methotrexate monotherapy (SC or intramuscularly) for induction of remission in adult outpatients with moderate-to-severe CD. C Avoid using oral methotrexate monotherapy for induction of remission in adult outpatients with moderate-to-severe CD. D As per ACG 2018 guidelines: Consider initiating methotrexate (up to 25 mg once weekly intramuscularly or SC) to alleviate signs and symptoms in patients with corticosteroid-dependent CD. C Do not use cyclosporine, mycophenolate mofetil, or tacrolimus in patients with CD. D As per AGA 2013 guidelines, avoid using methotrexate for induction of remission in patients with moderately severe CD. D Induction of remission, moderate-to-severe disease, thiopurines: As per AGA 2021 guidelines, avoid using thiopurine monotherapy for achieving remission in adult outpatients with moderate-to-severe CD. D As per ECCO 2020 guidelines, avoid using thiopurines as monotherapy for induction of remission in patients with moderate-to-severe luminal CD. D As per ACG 2018 guidelines: Do not use thiopurines (azathioprine or 6-mercaptopurine) for induction of short-term symptomatic remission in patients with CD unless as corticosteroid-sparing agents. D Consider obtaining TPMT testing before using azathioprine or 6-mercaptopurine in patients with CD. B As per AGA 2013 guidelines, avoid using thiopurine monotherapy for induction of remission in patients with moderately severe CD. D Induction of remission, moderate-to-severe disease, anti-TNFs: As per AGA 2021 guidelines, initiate anti-TNFs for induction of remission in adult outpatients with moderate-to-severe CD. B Show 6 more https://web.pathway.md/diseases/recFEepjgYMnE2bAn 8/28 6/23/23, 3:37 AM Crohn's disease Pathway As per ECCO 2020 guidelines: Initiate anti-TNF agents (infliximab, adalimumab, or certolizumab pegol) for induction of remission in patients with moderate-to-severe CD not responding to conventional therapy. B Avoid combining adalimumab with thiopurines to achieve clinical remission and response. D As per ACG 2018 guidelines, initiate anti-TNF agents (infliximab, adalimumab, certolizumab pegol) for the treatment of patients with corticosteroid-resistant CD. B Show 4 more As per AGA 2013 guidelines: Initiate anti-TNF agents for induction of remission in patients with moderately severe CD. Prefer anti-TNF monotherapy B or anti-TNF agents in combination with thiopurines over thiopurine monotherapy. A Consider initiating anti-TNF agents in combination with thiopurines over anti-TNF monotherapy for induction of remission in patients with moderately severe CD. C Induction of remission, moderate-to-severe disease, other biologics: As per AGA 2021 guidelines, initiate ustekinumab (Strong recommendation, moderate certainty evidence) or consider initiating for induction of remission in adult outpatients with moderate-to- severe CD never responded to anti-TNFs (primary nonresponse). B Show 4 more As per ECCO 2020 guidelines, initiate ustekinumab B or vedolizumab for induction of remission in patients with moderate-to-severe CD with inadequate response to conventional therapy and/or anti-TNF therapy. B As per ACG 2018 guidelines, consider initiating anti-integrin therapy (with vedolizumab) with or without an immunomodulator for induction of symptomatic remission in patients with moderate- to-severely active CD and objective evidence of active disease. B Show 2 more Maintenance therapy, medically induced remission, thiopurines: As per AGA 2021 guidelines, consider initiating thiopurine monotherapy for maintenance of remission in adult outpatients with quiescent moderate-to-severe CD (or patients in corticosteroid-induced remission). C As per ECCO 2020 guidelines, INITIATE thiopurines for maintenance of remission in patients with corticosteroid-dependent CD. B Show 2 more As per ACG 2018 guidelines: Consider initiating a thiopurine (azathioprine or 6-mercaptourine) or methotrexate once remission is induced with corticosteroids. B Initiate a thiopurine or methotrexate with or without anti-TNF therapy in corticosteroid- dependent patients. B As per AGA 2013 guidelines, initiate thiopurines for maintenance of corticosteroid-induced remission. B https://web.pathway.md/diseases/recFEepjgYMnE2bAn 9/28 6/23/23, 3:37 AM Crohn's disease Pathway Maintenance therapy, medically induced remission, methotrexate: As per AGA 2021 guidelines: Consider initiating methotrexate monotherapy (SC or intramuscularly) for maintenance of remission in adult outpatients with moderate-to-severe CD. C Avoid using oral methotrexate monotherapy for maintenance of remission in adult outpatients with moderate-to-severe CD. D As per ECCO 2020 guidelines, initiate parenteral methotrexate for maintenance of remission in patients with corticosteroid-dependent CD. B As per ACG 2018 guidelines, consider initiating a thiopurine or methotrexate once remission is induced with corticosteroids. B Show 2 more As per AGA 2013 guidelines, consider initiating methotrexate for maintenance of corticosteroid- induced remission. C Maintenance therapy, medically induced remission, anti-TNFs: As per AGA 2021 guidelines, initiate anti-TNFs for maintenance of remission in adult outpatients with moderate-to-severe CD. B Show 3 more As per ECCO 2020 guidelines, continue the same treatment for maintenance of remission in patients with CD achieved remission with anti-TNF agents. B Show 2 more As per ACG 2018 guidelines: Consider initiating anti-TNF therapy, specifically infliximab, adalimumab, or certolizumab pegol, for maintenance of anti-TNF-induced remission. B Consider combining anti-TNFs with azathioprine/6-mercaptopurine or methotrexate for maintenance of anti-TNF-induced remission because of the potential for immunogenicity and loss of response with anti-TNF monotherapy. B As per AGA 2013 guidelines: Initiate anti-TNF agents for maintenance of corticosteroid- or anti-TNF-induced remission. A Insufficient evidence to recommend for or against the combination of an anti-TNF agent and a thiopurine versus an anti-TNF agent alone for maintenance of remission induced by a combination of these agents in patients with CD. I Maintenance therapy, medically induced remission, other biologics: As per AGA 2021 guidelines, initiate ustekinumab B or consider initiating vedolizumab for maintenance of remission in adult outpatients with moderate-to-severe CD. B Show 2 more As per ECCO 2020 guidelines: Initiate vedolizumab for maintaining clinical remission in patients with moderate-to-severe CD achieved remission with vedolizumab. B https://web.pathway.md/diseases/recFEepjgYMnE2bAn 10/28 6/23/23, 3:37 AM Crohn's disease Pathway Initiate ustekinumab for maintaining clinical remission in patients with CD achieved remission with ustekinumab. B As per ACG 2018 guidelines, consider initiating vedolizumab for maintenance of vedolizumab- induced remission. C Show 2 more Maintenance therapy, medically induced remission, 5-ASAs: As per AGA 2021 guidelines, do not use 5-ASA or sulfasalazine for maintenance of remission in adult outpatients with moderate-to-severe CD. D As per ECCO 2020 guidelines, do not use oral 5-aminosalicylic acid for maintenance of medically induced remission in patients with CD. D As per ACG 2018 guidelines, do not use long-term oral 5-aminosalicylic acid for maintenance of medically induced remission in patients with CD. D Maintenance therapy, medically induced remission, corticosteroids: As per AGA 2021 guidelines, do not use corticosteroids for maintenance of remission in adult outpatients with moderate-to-severe CD. D As per ACG 2018 guidelines: Do not use long-term corticosteroids for maintenance of medically induced remission in patients with CD. D Do not use budesonide beyond 4 months for maintenance of remission in patients with CD. D Maintenance therapy, medically induced remission, antibiotics: As per ESPEN 2023 guidelines, insufficient evidence to recommend an antibiotic regimen for the maintenance of medically-induced remission. I As per ACG 2018 guidelines, do not use antimycobacterial agents for maintenance of remission in patients with CD. D Maintenance therapy, surgically induced remission: As per ACG 2018 guidelines, initiate prophylactic treatment after small intestinal resection in patients with risk factors for recurrence. E Show 6 more As per AGA 2017 guidelines, consider initiating early pharmacological prophylaxis, rather than endoscopy-guided pharmacological treatment, in patients with surgically induced remission. C Show 2 more Symptomatic therapy: Offer antidiarrheals, other nonspecific medications, and dietary manipulation for the treatment of symptoms in patients with low risk of progression, along with careful observation for inadequate symptom relief, worsening inflammation, or disease progression. B Avoid using NSAIDs in patients with CD, when possible, as they may exacerbate disease activity. D https://web.pathway.md/diseases/recFEepjgYMnE2bAn 11/28 6/23/23, 3:37 AM Crohn's disease Pathway Management of acute abdomen: ensure a multidisciplinary approach, involving a gastroenterologist and an acute care surgeon, B to decide on medical treatment in patients with IBD presenting with acute abdominal pain. B Show 3 more Management of intra-abdominal abscesses, antibiotics and drainage: As per ASCRS 2020 guidelines, consider administering antibiotics with or without drainage in patients with penetrating CD with abscess formation, followed by interval elective resection or medical therapy depending on the clinical situation and patient preferences. C As per ACG 2018 guidelines, administer antibiotics and perform a drainage procedure, either radiographically or surgically, in patients with an intra-abdominal abscess. B Management of intra-abdominal abscesses (anti-inflammatory therapy): consider administering infliximab if anti-inflammatory therapy for penetrating ileocecal CD is required, following adequate resolution of intra-abdominal abscesses in a multidisciplinary approach. C Management of anemia, iron supplementation: As per ESPEN 2023 guidelines, initiate iron supplementation in all patients with IBD and iron deficiency anemia, to correct anemia and normalize iron stores. B Show 2 more As per ECCO 2015 guidelines, initiate iron supplementation in all patients with IBD and iron deficiency anemia. A Show 4 more Management of anemia (RBC transfusion): consider administering RBC transfusion in patients with anemia with Hgb levels < 7 g/dL, or > 7 g/dL if symptoms or particular risk factors are present, followed by subsequent IV iron supplementation. C Management of anemia (monitoring of recurrence): Monitor patients with IBD for recurrent iron deficiency every 3 months for at least a year after correction, and 6-12 months thereafter. B Consider suspecting persistent intestinal disease activity in cases of recurrent anemia, even if there is clinical remission and inflammatory parameters (such as CRP) are normal. C Management of anemia (management of recurrence): Recognize that IBD-associated iron deficiency and anemia recur frequently and fast, even after treatment with IV iron, while the recurrence of iron deficiency is lower in patients with higher post-treatment ferritin levels. B Initiate re-treatment with IV iron as soon as serum ferritin drops < 100 g/L or Hgb < 12-13 g/dL (according to gender) after successful treatment of iron deficiency anemia with IV iron. B Management of anemia (management of non-IDA anemia): exclude other possible concomitant diseases, such as infections, malignancies, and side effects of medications, in the management of non-iron deficiency anemia in patients with IBD. B Show 4 more https://web.pathway.md/diseases/recFEepjgYMnE2bAn 12/28 6/23/23, 3:37 AM Crohn's disease Pathway 5. Inpatient care Thromboprophylaxis: administer VTE prophylaxis with LMWH as soon as possible in the emergency setting for the high risk of thrombotic events related to complicated IBD. A 6. Nonpharmacologic interventions Smoking cessation: advise patients with CD to quit smoking as it exacerbates disease activity and accelerates disease recurrence. Encourage active smoking cessation programs. B Physical activity: encourage endurance training in all patients with IBD. Advise appropriate physical activity (mainly resistance training) in patients with IBD with decreased muscle mass and/or muscle performance. B Nutritional support (counseling): Provide individual counseling by a dietitian as part of the multidisciplinary approach to improve nutritional therapy and avoid malnutrition and nutrition-related disorders in all patients with IBD, B as well as regarding malabsorption or maldigestion in patients with CD. B Counsel patients with IBD with hyperoxaluria regarding fat malabsorption as they often also have fat malabsorption. B Nutritional support, general principles: As per ESPEN 2023 guidelines: Obtain nutritional screening and deliver dietary management by a multidisciplinary IBD team including nurses. B Insufficient evidence to recommend an "IBD diet" to promote remission in patients with IBD with active disease. I As per AAST/WSES 2021 guidelines, provide nutritional support (parenteral or enteral, according to gastrointestinal function and in conjunction with a dietitian/nutrition team) as soon as possible. B Nutritional support (exclusion diet): Consider offering a CD exclusion diet, with or without enteral nutrition, in adult patients with mild-to-moderately active CD. C Consider offering a CD exclusion diet with partial enteral nutrition as an alternative to exclusive enteral nutrition to achieve remission in pediatric patients with mild-to-moderately active CD. C Nutritional support (oral nutritional supplements): Offer oral nutritional supplements as the first step when medical nutrition is indicated in patients with IBD, as supportive therapy in addition to regular food. B Consider offering oral nutritional supplements or enteral nutrition in patients with CD in remission if malnutrition cannot be treated sufficiently by dietary counseling. C Nutritional support (enteral nutrition): consider initiating enteral nutrition as supportive therapy if oral feeding is insufficient. Consider preferring enteral nutrition using formulas or liquids over https://web.pathway.md/diseases/recFEepjgYMnE2bAn 13/28 6/23/23, 3:37 AM Crohn's disease Pathway parenteral nutrition unless completely contraindicated. C Show 8 more Nutritional support, parenteral nutrition: As per ESPEN 2023 guidelines, initiate parenteral nutrition in patients with IBD in the following situations: oral or enteral nutrition is not sufficiently possible, such as dysfunctional gastrointestinal tract or CD with short bowel bowel obstruction with no possibility of placement of a feeding tube beyond the obstruction, or if these attempts have failed other complications, such as an anastomotic leak or a high output intestinal fistula. B Show 3 more As per AAST/WSES 2021 guidelines: Reserve TPN for nutritionally deficient patients unable to tolerate enteral nutrition and when the enteral route is contraindicated, in critically ill patients presenting with signs of shock, intestinal ischemia, high output fistula, and/or severe intestinal hemorrhage. B Initiate TPN as the mode of choice in patients with complicated IBD requiring emergency surgery. A Nutritional support (energy requirements): ensure energy intake of 30-35 kcal/kg/day in patients with IBD, as their requirements are similar to the healthy population. Determine individual energy requirements using indirect calorimetry and an individual physical activity factor if there is a clinical suspicion of a different energy requirement in particular disease states. B Nutritional support (protein requirements): Ensure protein intake of ~ 1 g/kg/day in adult patients with IBD in remission, as their requirements are similar to the general population. B Increase protein intake to 1.2-1.5 g/kg/day in adult patients with active IBD. B Nutritional support (micronutrient requirements): assess for micronutrient deficiencies regularly in patients with IBD, including in the remission phase, and correct specific deficits appropriately. B Nutritional support (vitamin supplements): initiate vitamin B12 supplementation in patients with CD when > 20 cm of the distal ileum is resected, whether or not in combination with the ileocecal valve, or when vitamin B12 deficiency is documented. B Show 2 more Nutritional support (management of malnutrition): screen for malnutrition at the time of diagnosis and regularly thereafter in patients with IBD. B Show 2 more Nutritional support (avoidance of dehydration): make every effort to avoid dehydration in patients with IBD. B Nutritional support (avoidance of refeeding syndrome): consider undertaking standard precautions and interventions to prevent the refeeding syndrome, particularly concerning https://web.pathway.md/diseases/recFEepjgYMnE2bAn 14/28 6/23/23, 3:37 AM Crohn's disease Pathway phosphate and thiamine, in patients with IBD and nutritional deprivation extended over many days. C Probiotics: As per ESPEN 2023 guidelines: Do not offer probiotics for the treatment of active disease or for the prevention of relapse in the remission phase or postoperative recurrence of disease in patients with CD. D Do not offer prebiotics for the treatment of CD, neither in active disease nor for maintenance of remission. D As per AGA 2020 guidelines, offer probiotics in patients with CD only in the context of a clinical trial. B 7. Therapeutic procedures Fecal microbiota transplantation: insufficient evidence to recommend for or against fecal microbiota transplantation in patients with IBD. I 8. Perioperative care Preoperative medications: As per WSES 2021 guidelines: Wean off corticosteroids (preoperatively, ideally 4 weeks) and stop anti-TNFs before surgery, as soon as possible to decrease the risk of postoperative complications, in accordance with a gastroenterologist. B Recognize that preoperative anti-TNFs and corticosteroids are risk factors for intra-abdominal sepsis in patients requiring emergency resectional surgery. B As per ASCRS 2020 guidelines, attempt weaning corticosteroids before surgical intervention as preoperative high-dose corticosteroids increase the risk of postoperative infectious complications. B Show 2 more As per ECCO 2019 guidelines, consider reducing the dose of corticosteroids preoperatively, with a careful monitoring to avoid increasing disease burden, in order to reduce the rates of postoperative complications. C Show 2 more Perioperative nutrition: As per ESPEN 2023 guidelines, assess nutritional status before planned surgery. Administer dietetic interventions including nutritional therapy in patients with malnutrition or at nutritional risk. B Show 10 more As per WSES 2021 guidelines, provide preoperative nutritional support in severely undernourished patients. A https://web.pathway.md/diseases/recFEepjgYMnE2bAn 15/28 6/23/23, 3:37 AM Crohn's disease Pathway As per ASCRS 2020 guidelines, consider providing preoperative nutritional support to decrease postoperative morbidity in patients with malnutrition. C As per ECCO 2019 guidelines, obtain preoperative nutritional assessment in all patients with CD planned to undergo surgery. Optimize nutritional status with enteral or parenteral nutrition before surgery in patients with nutritional deficiencies. B Preoperative smoking cessation: advise smoking cessation to reduce postoperative morbidity in patients with CD. B 9. Surgical interventions Indications for surgery, refractory disease: As per AAST/WSES 2021 guidelines: Perform surgical exploration by laparotomy in hemodynamically unstable patients with severe colitis not responding to medical treatment, taking into consideration damage control surgery principles with or without an open abdomen. B Perform subtotal colectomy with ileostomy in patients presenting with acute severe refractory colitis, and massive colorectal bleeding not responding to medical treatment, in a laparoscopic or open approach according to patient's hemodynamic stability and surgeon's skills. B As per ASCRS 2020 guidelines: Perform surgery in patients with severe acute colitis not adequately responding to medical therapy. B Consider performing surgery in patients with an inadequate response to, developing complications from, or being nonadherent with medical therapy. B Indications for surgery, hemorrhage: As per AAST/WSES 2021 guidelines, consider performing sigmoidoscopy and upper gastrointestinal endoscopy in hemodynamically stable patients with IBD presenting with gastrointestinal bleeding. C Attempt preoperative localization of the bleeding site with the aim of excluding upper gastrointestinal or anorectal bleeding to allow better planning of the surgical strategy. C Show 6 more As per ASCRS 2020 guidelines, consider evaluating and treating stable patients with gastrointestinal hemorrhage by endoscopic and/or interventional radiologic techniques. Perform operative exploration in unstable patients despite resuscitation efforts. B Indications for surgery, perforation: As per AAST/WSES 2021 guidelines, perform surgical exploration in the presence of radiological signs of pneumoperitoneum and free fluid within the peritoneal cavity in acutely unwell patients presenting with complicated CD or acute severe ulcerative colitis. B Show 4 more As per ASCRS 2020 guidelines: Perform surgery in patients with signs or symptoms of impending or actual perforation. B https://web.pathway.md/diseases/recFEepjgYMnE2bAn 16/28 6/23/23, 3:37 AM Crohn's disease Pathway Perform surgical resection of the perforated segment in patients with free perforation. B Indications for surgery, strictures: As per AAST/WSES 2021 guidelines, perform surgery in patients with CD with symptomatic intestinal strictures not responding to medical therapy and not amenable to endoscopic dilatation. B Show 3 more As per ASCRS 2020 guidelines, consider performing endoscopic dilation in patients with short- segment, non-inflammatory, symptomatic small bowel or anastomotic strictures. B Show 4 more As per ECCO 2019 guidelines, defer surgery in adult patients with CD presenting with acute small bowel obstruction without bowel ischemia or peritonitis. B Show 2 more Indications for surgery (toxic megacolon): perform surgical exploration by laparotomy in hemodynamically unstable patients presenting with toxic megacolon, taking into consideration damage control surgery principles with or without an open abdomen. B Show 3 more Indications for surgery, abdominal abscess: