Stool

• Stool should be fresh and warm, given to laboratory within 1 hour after collection
• Stool specimen amount: 15-30 ml or 1 inch
• Collect small portion of the stool with blood or mucus, if none at the center. Look for anything unusual
• Purpose of Guaiac test: To detect GI bleeding
• FOBT

  False Positive Causes

  • Dark-colored foods for 3 days
  • Iron, NSAIDs, steroids for 7 days

  False Negative Causes

  • >250mg of Vit C