Anal fissure

Hemorrhoids

Colonic diverticula

Colorectal cancer

Inflammatory bowel disease

Infectious colitis

Salmonella

Shigella

Campylobacter

Amoeba

E. coli 0157:H7

Ischemic colitis

Vascular anomalies

Angiodysplasia/ectasia

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu)

Arteriovenous malformation

Solitary rectal ulcer syndrome

Aortoenteric fistula

Meckel’s diverticulum

Duodenal/jejunal diverticula

Small bowel neoplasms

NSAID-related small bowel ulcers

NSAID-related colonic ulcers