Upper Gastrointestinal Crohn's Disease: Shedding Light on the Obscure L4 Classification Meaning

Area of Science:

• Gastroenterology
• Inflammatory Bowel Disease
• Clinical Research

Background:

• Upper gastrointestinal Crohn's disease (UGI-CD) is inconsistently defined and underrecognized.
• Lack of a unified definition hinders epidemiological studies, diagnosis, and tailored patient care.
• Absence of segment-specific criteria impedes study reproducibility and comparability.

Purpose of the Study:

• To synthesize current knowledge on UGI-CD definitions, prevalence, diagnosis, and management.
• To identify gaps and propose a pragmatic approach for UGI-CD.
• To highlight research priorities for improving UGI-CD recognition and outcomes.

Main Methods:

• Narrative synthesis of adult and pediatric studies and major guidelines.
• Examination of definitions, prevalence, diagnosis, and management strategies.
• Mapping findings to specific upper GI segments (esophagus, stomach, duodenum, proximal small bowel).

Main Results:

• UGI-CD definitions are heterogeneous, with variable prevalence.
• Diagnosis involves esophagogastroduodenoscopy, biopsies, cross-sectional imaging, and enteroscopy.
• Anti-TNF agents are effective for esophagogastroduodenal disease; management requires segment-tailored monitoring.

Conclusions:

• UGI-CD remains poorly standardized in definition, epidemiology, and management.
• A pragmatic diagnostic and monitoring pathway is proposed.
• Research priorities include segment-based reporting, upper GI-only cohorts, and treatment target validation.