Summary
Definition
History and exam
Key diagnostic factors
- abdominal pain
- prolonged diarrhea
- perianal lesions
Other diagnostic factors
- bowel obstruction
- blood in stools
- fever
- fatigue
- abdominal tenderness
- weight loss
- oral lesions
- abdominal mass
- extraintestinal manifestations (e.g., erythema nodosum or pyoderma gangrenosum)
Risk factors
- white ethnicity and Ashkenazi Jewish ancestry
- age 15-40 or 50-60 years
- family history of CD
- cigarette smoking
- diet high in refined sugar
- diet low in fiber
- diet high in ultra-processed foods
- oral contraceptives
- not breastfed
- nonsteroidal anti-inflammatory drugs (NSAIDs)
Diagnostic investigations
1st investigations to order
- CBC
- iron studies (serum iron, serum ferritin, total iron binding capacity [TIBC], transferrin saturation)
- serum vitamin B12
- serum folate
- comprehensive metabolic panel (CMP)
- C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)
- stool testing
- Yersinia enterocolitica serology
- plain abdominal x-ray
- MRI abdomen/pelvis
- CT abdomen
Investigations to consider
- abdominal and pelvic ultrasonography
- ileocolonoscopy
- tissue biopsy
- esophagogastroduodenoscopy
- wireless capsule endoscopy
- fecal calprotectin or fecal lactoferrin
Emerging tests
- serologic markers
Treatment algorithm
ileocecal disease not fistulizing with <100 cm of bowel affected: initial presentation or relapse
colonic disease not fistulizing: initial presentation or relapse
extensive small bowel disease (>100 cm of bowel affected) not fistulizing: initial presentation or relapse
upper gastrointestinal disease (esophageal and/or gastroduodenal disease) not fistulizing: initial presentation or relapse
perianal or fistulizing disease: initial presentation or relapse
in remission
Contributors
Authors
George Reese, MBBS, FRCS
Consultant Colorectal Surgeon
Imperial College Healthcare NHS Trust
London
UK
Disclosures
GR is an author of a number of references cited in this topic.
Georgia Woodfield, MBChB, MSc, PhD
Specialist Registrar in Gastroenterology and General Medicine
Imperial College Healthcare NHS Trust
Research Fellow
Imperial College London
London
UK
Disclosures
GW declares that she has no competing interests.
Pranav H. Patel, MD
Specialist Registrar in General Surgery
Imperial College Healthcare
Research Fellow
Imperial College London
London
UK
Disclosures
PHP declares that he has no competing interests.
Acknowledgements
Mr George Reese, Dr Georgia Woodfield, and Dr Pranav H. Patel would like to gratefully acknowledge Dr Philip J. Smith, Dr Charlotte Ford, Dr Wissam Bleibel, Dr Bishal Mainali, Dr Chandrashekhar Thukral, and Dr Mark A. Peppercorn, the previous contributors to this topic.
Disclosures
PJS, CF, WB, BM, CT, and MAP declare that they have no competing interests.
Peer reviewers
Kiron M. Das, MD, PhD, FACP, FRCP
Chief of Gastroenterology & Hepatology
Professor of Medicine
Director of Crohn's & Colitis Center of New Jersey
New Brunswick
NJ
Disclosures
KMD declares that he has no competing interests.
John Mansfield, MA, MD, FRCP
Consultant Gastroenterologist and Senior Lecturer
Royal Victoria Infirmary
Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University
Newcastle upon Tyne
UK
Disclosures
JM declares that he has no competing interests.
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