Inflammation-related:
(1) esophagitis with or without ulceration
(2) gastritis with or without ulceration
(3) hiatal hernia (Cameron’s erosions)
(4) duodenitis with or without ulceration
(5) celiac sprue
(6) Crohn’s disease
(7) ulcerative colitis
(8) ischemic colitis
(9) other forms of colitis
(10) parasitic infection
(11) infectious enteritis (tuberculous, bacterial, viral)
(12) radiation-induced
Tumor-related:
(1) polyp(s)
(2) benign tumor (including hemangioma)
(3) primary malignant tumor
(4) metastatic tumor
Vascular-related:
(1) varices
(2) gastric antral vascular ectasia (watermelon stomach)
(3) portal gastropathy
(4) Dieulafoy’s lesion in the stomach
(5) blue rubber bleb nevus syndrome
(6) angiodysplasia or vascular ectasia
(7) telangiectasia
(8) amyloidosis
(9) vasculitis
(10) aortoenteric fistula (rarely occult)
(11) other arteriovenous lesion
Other:
(1) diverticuli
(2) Meckel’s diverticulum
(3) anal fissure
(4) hemorrhoids
(5) running or other exercise
(6) surgical anastomosis
(7) splenosis
Extra-intestinal bleeding:
(1) epistaxis
(2) bleeding gums
(3) pulmonary (hemoptysis)
(4) hemobilia
(5) bleeding from the pancreas
Non-bleeding:
(1) factitious
(2) blood in diet
(3) false-positive test for fecal blood
Drugs that may contribute to bleeding:
(1) anticoagulants
(2) NSAIDS
(3) other medications
