Table 1.

Main clinical, endoscopic, and pathological features of gastrointestinal involvement in Behçet's disease and most common localization.

	Behçet's disease	Crohn's disease	Ulcerative colitis
Gastrointestinal manifestations	Anorexia, vomiting, dyspepsia, diarrhoea, abdominal pain, melena, hematochezia, fever	Anorexia, vomiting, dyspepsia, diarrhea, gastrointestinal bleeding, abdominal pain, fever	Rectal bleeding, diarrhoea, tenesmus, abdominal pain, hematochezia, fever
Pathological features	Vasculitis of the small veins and venules with deep ulcerations, generally without granulomas or cobblestoning, ischemic perforation, thrombosis	Transmural mucosal inflammation, inflammatory cell infiltrate (lymphocytes, plasma cells) with focal crypt irregularity and independent granulomas	Distortion of crypt architecture, crypt abscesses, lamina propria cellular infiltration (plasma cells, eosinophils, lymphocytes), shortening of the crypts, mucin depletion, lymphoid aggregates, erosions or ulcerations
Endoscopic findings	Round or oval ulcers, punched-out lesions with discrete margins (>1 cm), focal distribution (<5 ulcers)	Longitudinal ulcers, cobblestone appearance, aphthous ulcers showing longitudinal array	Mucosal erythema, fine granularity, loss of vascular marking, erosions, ulcers, spontaneous bleeding, luminal narrowing with pseudopolyps
Localization	Terminal ileum, ileocecal region, colon	Small bowel, upper-gastrointestinal tract	Starts in the rectum and extends proximally in a continuous manner through the entire colon