The evaluation of gastrointestinal bleeding begins with a history and physical examination.

Physical findings in someone with gastrointestinal bleeding may include:

• Blood in the stools on rectal examination (stool guaiac) that may appear as:
• Black stool
• Maroon stool
• Rectal bleeding
• Red stools
• Upper abdominal tenderness
• Rapid pulse
• Low blood pressure

Tests are necessary to evaluate gastrointestinal bleeding.

Tests that may be used to evaluate gastrointestinal bleeding include:

• Stool guaiac:
• Can detect minute quantities of blood in the stool
• Pulse oximetry
• Complete blood count
• To check for anemia due to chronic blood loss
• Coagulation profile
• Serum amylase
• Serum lipase
• Serum gastrin levels:
• Can detect Zollinger-Ellison syndrome
• Serum iron level and TIBC
• Serum B12 level
• Serum folate level
• Tests for Helicobacter pylori infection:
• Helicobacter pylori breath test
• Helicobacter pylori blood test
• Helicobacter pylori biopsy test
• Helicobacter pylori stool test
• Upper GI series:
• A barium x-ray study of the stomach and upper intestines
• Upper GI endoscopy:
• Allows direct inspection of the stomach and duodenum
• Selective arteriography and radionuclide scanning of the intestines.
• Anoscopy
• Colonoscopy:
• Allows a doctor to look inside, take tissue specimens, and remove any questionable growths or polyps.
• Sigmoidoscopy:
• Allows a doctor to look inside, take tissue specimens, and remove any questionable growths or polyps.