Occult Blood

What Causes Occult Blood?

Occult blood can have various causes, just like most other symptoms.  Finding the true cause means ruling out or confirming each possibility – in other words, diagnosis.

Diagnosis is usually a complex process due to the sheer number of possible causes and related symptoms.  In order to diagnose occult blood, we could:
  • Research the topic
  • Find a doctor with the time
  • Use a diagnostic computer system.
The process is the same, whichever method is used.

Step 1: List all Possible Causes

We begin by identifying the disease conditions which have "occult blood" as a symptom.  Here are eight of many possibilities:
  • Ulcerative Colitis
  • Stomach Ulcers
  • Crohn's Disease
  • Rectal Cancer
  • Colon Cancer
  • Carcinoid Cancer
  • Small Intestine Cancer
  • Stomach Cancer

Step 2: Build a Symptom Checklist

We then identify all possible symptoms and risk factors of each possible cause, and check the ones that apply:
very frequent stools
major mid-abdomen pain after food
weak appetite
severe meal-induced pain
infrequent meal-induced pain
having watery stools
significant red blood in stools
severe abdominal pain
frequent unexplained nausea
mild right iliac discomfort
nausea for 1-3 months
stomach cancer
... and more than 80 others

Step 3: Rule Out or Confirm each Possible Cause

A differential diagnosis of your symptoms and risk factors finds the likely cause of occult blood:
Cause Probability Status
Stomach Ulcers 94% Confirm
Carcinoid Cancer 21% Unlikely
Crohn's Disease 27% Unlikely
Rectal Cancer 5% Ruled out
Stomach Cancer 3% Ruled out
Colon Cancer 3% Ruled out
Small Intestine Cancer 2% Ruled out
Ulcerative Colitis 1% Ruled out
* This is a simple example to illustrate the process

Arriving at a Correct Diagnosis

The Analyst™ is our online diagnosis tool that learns all about you through a straightforward process of multi-level questioning, providing diagnosis at the end.

If you indicate having had recent lab tests, The Analyst™ will ask further questions including this one:
Occult blood. Have lab tests found blood in your stool within the past 6 months?
Possible responses:
→ Not tested within past 6 months / don't know
→ No, stool tested negative
→ In the past only, now resolved
→ Yes, trace or small amounts
→ Yes, enough for doctor to be concerned
Based on your response to this question, which may indicate absence of occult blood, history of occult blood, trace amounts of occult blood or significant amounts of occult blood, The Analyst™ will consider possibilities such as:
... and also rule out issues such as: