Duration Of Current Diarrhea Symptom

What Causes Chronic Diarrhea?

Chronic diarrhea can have various causes, ranging in severity from 'minor' to 'very serious'.  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 chronic diarrhea, 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 "chronic diarrhea" as a symptom.  Here are eight of many possibilities (more below):
  • Blastocystosis
  • Hyperthyroidism
  • Stress
  • Lactose Intolerance
  • Epstein-Barr Virus
  • Short Bowel Syndrome
  • West Nile Virus
  • Rapid Stool Passage

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:
Latin / Hispanic ethnicity
severe emotional instability
frequent unexplained nausea
blood transfusions
offensive-smelling stool
short-term memory failure
severe lactose intolerance
edema of the hands
dizziness when standing up
biliopancreatic diversion
frequent unexplained fevers
low TSH
... and more than 120 others

Step 3: Rule Out or Confirm each Possible Cause

A differential diagnosis of your symptoms and risk factors finds the likely cause of chronic diarrhea:
Cause Probability Status
Short Bowel Syndrome 95% Confirm
West Nile Virus 29% Unlikely
Blastocystosis 18% Unlikely
Rapid Stool Passage 2% Ruled out
Stress 2% Ruled out
Epstein-Barr Virus 0% Ruled out
Lactose Intolerance 0% Ruled out
Hyperthyroidism 0% 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 irregular stools, The Analyst™ will ask further questions including this one:
If you suffer significantly from diarrhea (at least once per week), for how long has this been a problem?
Possible responses:
→ It is not a problem / don't know
→ It started within the last week
→ It started within the last month
→ I've had it for 1 to 3 months
→ I've had it for over 3 months
Based on your response to this question, which may indicate no significant diarrhea, recent onset diarrhea, diarrhea for 1-3 months or chronic diarrhea, The Analyst™ will consider possibilities such as:
IBS (Irritable Bowel Syndrome)

Most people with IBS have intermittent bouts of diarrhea.

Rapid Intestinal Transit

Rapid passage (or transit) of stool is one of the most common causes of diarrhea.  Stool that leaves the large intestine too quickly is watery: there is not enough time for fluid and nutrients to be absorbed from the contents of the gastrointestinal tract.

Rapid Intestinal Transit also suggests the following possibilities:


Stress and anxiety are common causes of rapid food transit through the intestines.

Vitamin B12 Requirement

Intermittent diarrhea can be a sign of B12 deficiency.