spelling



steatorrhea



basis for excess of fluid in stool


gut balance of secretory and absorptive fluxes - implications

possible mechanisms for excess water loss


• loss of or damage to of absorptive surface while secretion continues
  
  
• disruption of balance between absorption and secretion by osmotic forces
  
  
• large increase in secretion with inadequate absorption
  
  
• overactive motility causing rapid transit and so inadequate time for absorption
  

classification of cases of diarrhea into four categories:

• 'reduced contact' with absorptive mucosa
  
  
• 'osmotic' diarrhea
  
  
• 'secretory' diarrhea
  
  
• 'inflammatory' diarrhea
  

References and Advanced Reading (links valid May 2005). James Christensen's chapter 4 of the Bedside Logic in Diagnostic Gastroenterology, on Diarrhea. Clearly written and considerable detail in one long page. Estes MK et al: Pathogenesis of rotavirus gastroenteritis p. 82 in Gastroenteritis Viruses (Novartis Symposium 238). Wiley, 2001. Philson Library. Abstract available at http://www.novartisfound.org.uk/catalog/238abs.htm#estes or a cached copy here. Toddler's diarrhea: http://adc.bmjjournals.com/cgi/content/full/archdischild;79/1/2.

Sample multiple-choice question for discussion. A 12 month old child has had frequent yellowish-coloured watery motions today. Your initial recommendation is... (a) oral paregoric (opiate-based compound to reduce motility and enteric secretion) (b) stool culture and microscopy testing before treatment (c) IV saline or Ringer's 10ml/kg body weight/hr then depending on serum electrolytes (d) ciprofloxacin syrup (quinolone antibiotic) for Campylobacter jejuni enteritis (e) oral rehydration solution containing glucose, NaCl and NaHCO3

The Big Picture: function of the gastrointestinal tract Intestinal Function 1. Gut Reactions: immune function, motility and (exocrine) secretion Intestinal Function 2. Crossing the Border: fluid and nutrients at the epithelium