Medical Council of Canada

Medical expert

Chronic Diarrhea - 22-2


Chronic diarrhea is defined as a disturbance of stool frequency and/or consistency of greater than four weeks' duration.

Causal Conditions

(list not exhaustive)
  1. Steatorrhea
    1. Luminal
      1. Pancreatic insufficiency
      2. Cholestasis
      3. Ileal disease or resection
      4. Bacterial overgrowth
    2. Mucosal
      1. Lactase deficiency
      2. Celiac disease
  2. Large bowel
    1. Secretory diarrhea (e.g., villous adenoma)
    2. Inflammatory diarrhea
      1. Inflammatory bowel disease
      2. Infection
      3. Other (e.g., radiation, ischemic colitis)
    3. Motility disorder (e.g.,irritable bowel syndrome)
  3. Small bowel
    1. Osmotic diarrhea
    2. Secretory diarrhea
      1. Tumors
        1. Neuroendocrine (e.g., carcinoid)
        2. Neoplasia (e.g., lymphoma)
      2. Mucosal
    3. Motility disorders (e.g., diabetic neuropathy)

Key Objectives

Given a patient with chronic diarrhea, the candidate will diagnose the cause, severity, and complications, and will initiate an appropriate management plan. In particular, the history should focus on contrasting small and large bowel diarrhea.

Enabling Objectives

Given a patient with chronic diarrhea, the candidate will

  1. list and interpret clinical findings, including
    1. differentiate pancreatic and biliary causes from small bowel and large bowel causes of diarrhea;
    2. differentiate osmotic from secretory diarrhea;
    3. differentiate maldigestion from malabsorption;
    4. diagnose irritable bowel syndrome on the basis of history and appropriate exclusion of other causes;
  2. list and interpret critical investigations, including
    1. select and interpret investigations for malabsorption and specific underlying causes;
    2. select and interpret investigations for other causes of chronic diarrhea;
  3. construct an effective initial management plan, including
    1. prevent, recognize, and treat related complications (e.g., other manifestations of inflammatory bowel disease);
    2. select patients in need of specialized care or consultation;
    3. conduct education and counseling of patients with malabsorption and inflammatory bowel disease.
Next: Pediatric Diarrhea