| Upper GI tract |
| Peptic ulcer disease | Use of aspirin, NSAIDs, or tobacco |
| Esophageal varices | Alcohol abuse; jaundice; signs of portal hypertension, including: ascites, palmar erythema, spider angiomata, hepatomegaly, splenomegaly, and rectal varices |
| Mallory-Weiss tear | Bleeding preceded by vomiting, retching, or seizures |
| Gastric cancer | Left supraclavicular adenopathy; palpable mass; abdominal pain; weight loss; cachexia |
| Lower GI tract |
| Diverticular disease | Age > 60 years; painless bleeding; possible recent constipation |
| Arteriovenous malformations | Age > 60 years; painless bleeding; chronic renal failure |
| Colonic neoplasms | Age > 50 years; abdominal pain; weight loss; muscle wasting; protein calorie malnutrition; right-sided colon cancer may be associated with palpable right-sided abdominal mass; hepatomegaly; liver nodules; history of adenomatous polyps or longstanding ulcerative colitis; prior exposure to ionized radiation; family history of familial polyposis coli or cancer family syndrome |
| Inflammatory bowel disease | Ulcerative colitis: starts in younger patients (20 to 40 years of age); usually involves the rectum; associated with diarrhea mixed with blood and mucus |
| | Crohn’s disease: starts in younger patients (20 to 40 years of age); perianal, peritoneal, and/or abdominal wall fistulas may be associated |
| Radiation colitis | History of radiation treatment to abdomen and/or pelvis |
| Hemorrhoids | Perianal mass may be painful (external hemorrhoid) or painless (internal hemorrhoid); commonly starts in younger patients; associated with constipation, pregnancy, or postpartum period |
| Anal fissures | More common in patients with history of constipation; associated with severe sharp pain occurring with straining on defecation; pain resolves within an hour after defecation; commonly starts at 20 to 40 years of age |
| Colon tuberculosis | History of pulmonary tuberculosis or past exposure to tuberculosis |
| Aortoduodenal fistula | History of abdominal aortic aneurysm surgically repaired with synthetic vascular graft placement |