Gastroenterology Diarrhea: Acute and Chronic Aspects, Saint Camillus University

Diarrhea: A Universal Human Experience

Diarrhea: a universal human experience
4th most common GI symptom prompting an amb. Health care visit
6th most common GI-based physician diagnosis
7.5% of Americans
ACUTE GASTROENTERITIS /month
- Duration
. For most, lasts a day or 2
. For others >few days or is complicated by fever, bleeding ...
- Health burden
· 3.500.000 outpatient visits /year in USA
· 180.000 hospital admissions
· 3.000 deaths
5-7% of Americans
CHRONIC DIARRHEA (>4wks)

Diarrhea Definition and Stool Consistency

Diarrhea: definition
· STOOLS CONSISTENCY: LOOSE OR WATERY ?difficult (visual scales)
•
FREQUENCY
≥3 times/day
· STOOL WEIGHT >200 g/day (in the West)
10 g/kg body weight infants
85% water content

Bristol Stool Chart

Bristol Stool Chart
Type I
Separate hard lumps, like nuts
(hard to pass)
Type 2
Sausage-shaped but lumpy
Type 3
Like a sausage but with cracks on
its surface
Type 4
Like a sausage or snake, smooth
and soft
Type 5
Soft blobs with clear-cut edges
(passed easily)
Type 6
Fluffy pieces with ragged edges, a
mushy stool
Type 7
Watery, no solid pieces.
Entirely Liquid

Physiology: Ions and Water Intestinal Transport

Physiology:
lons and Water Intestinal Transport
· lons & Water move bidirectionally from luminal (mucosal) to blood
(serosal) sides and vice versa
· the "net" ion flux (the difference between the 2 unidirectional fluxes)
determines the direction of net transport
· ACTIVE transport of ions (principally Na+, CI-, HCO3-) provides the
electrical and chemical forces that drive the coupled absorption of
nutrients, and the net absorption or secretion of water.
· ABSORPTIVE AND SECRETORY AGENTS (local and systemic
hormones, neurotransmitters, toxins, other intraluminal molecules)
stimulate ion and water transport

Physiology: Solutes Intestinal Absorption

Physiology:
Solutes Intestinal Absorption
· ACTIVE transport mediated by membrane-associated
channels and transporters
· traverse the epithelium through 2 other mechanisms
referred to as INTESTINAL PERMEABILITY:
- Endocytotic uptake from the lumen (intracellular pathway)
- Exocytotic delivery through the tight junctions to the
basolateral compartment (intercellular transport or paracellular
pathway)

Intestinal Regulatory System and Fluid Dynamics

ALPINES intestinal regulatory system
Paracrine
Immune
Neural
Luminal
Endocrine
Autocrine
systems
structures
Paracellular
Blood
flow
Epithelium
Muscle
Permeability
Passive transmucosal
elecrolytes
Transport
Active, nutrients
& electrolytes
Motility
Metabolism
cellular

Normal Intestinal Fluid Dynamics

Intestinal fluid dynamics
normal conditions
Secretions:
saliva
1.5 L
gastric
2.5 L
bilio + pacreatic
0.5 + 1.5 L
small bowel
1 L
Absorption
8.5 L in the SMALL BOWEL
· 2.5 ml/min during fasting
· 5ml/min after meals
1.5 L in the COLON
. 0.3 ml/min during fasting
. 0.6 ml/min postprandially
10 L
Oral intake 1.5 L
0,2 L
STOOL

Diarrhea and Hypersecretion

Intestinal fluid dynamics
DIARRHEA
Secretions
Absorption
Oral intake
2,0hypersecretion
Ach TK 5HT
IP
PĚ#CO3toxins
Bacteria Vir
water
Adenilciclase
Guanilciclase
Fosfolipase C
Na+
Adenilciclase
Guanilciclase
Fosfolipase C
K+
Ca++
CAMP
CGMP
CAMP
Ca++ cGMP
Na+ Cl- water
Cl-
K+ HCO3-

Hypersecretion Diarrhea: Cholera Example

Hypersecretion diarrhea
Cholera best physiopath example
Cholera Toxins
· produce a secretory state through
- adenylate cyclase (enterocyte)
- elements of the regulatory system: neurons, enterochromaffin cells
secreting PG, serotonin (5HT) vasoactive intest. peptide
· increase permeability of the tight junction

Decreased Absorption and Increased Osmotic Load

Decreased absorption
damaged or undiff cell
normal cell
inflammation
Increased transit
Increased osmotic
water
time
load (>390)
Na+
Cl-
.

Types of Diarrhea

Secretory Diarrhea

Secretory Diarrhea
Exogenous
-ALIMENTARY:
-allergens, coffe, cola, tea, seafood toxin (ciguatera,
scombroid, shellfish toxins), amanita phalloides
-DRUGS:
-Laxatives (bysacodyl, senna), aloe, theophylline,
cholinenergic drugs, furosemide, colchicine
-INFECTIVE:
-Cholera, E.coli enterotoxic
Endogenous
-HORMONS:
-Producing tumors (VIP, gastrin), hypertyroidism,
Addison dis., diabetes
-VILLOUS TUMORS (Polyps, Cancer)
-others PG, long-chain fatty acids, bile acids

Inflammatory Diarrhea

Inflammatory Diarrhea
Exogenous
-INFECTIVE:
-Bacterial: E. Coli enteroinvasive, Staphylococco, Salmonella,
Shigella, Clostridium D., Campylobacter
-Viral: Adenovirus, Rotavirus
-Protozoal: Giardia
-PHARMACOLOGIC:
-Antibiotics, cytostatics, Drugs, MetilDopa, NSAIDs, PPI
-others:
-Toxics (Cocaine), Rx, food allergy
Endogenous -INFLAMMATORY:
-IBD: ulcerative colitis, Crohn's disease
-Microscopic colitis
-Ischemic colitis
-Eosinophilic enteritidis

Osmotic Diarrhea

Osmotic Diarrhea
Exogenous
-ALIMENTARY:
-High fiber diet
-PHARMACOLOGIC:
-Laxatives
Endogenous
-MALABSORPTION:
-Celiac Disease, small intestine bacterial
overgrowth (SIBO), Protozoal, surgery
-MALDIGESTION:
-Chronic Pancreatitis, Lactase deficiency
-Cystic Fibrosis

Diarrhea: History and Severity Assessment

Diarrhea: History
DURATION: < 4wks vs >4 weeks
FREQUENCY: continuous vs intermittent,
nocturnal, meal-related
STOOL APPEARANCE: bloody, fatty, watery
FECAL INCONTINENCE
EPIDEMIOLOGY
- Recent foreign travel
- Pt occupation and sexual orientation
IATROGENIC FACTORS: radiation, surgery,
laxative use, alcohol & illicit drugs
SYSTEMIC DISEASES: endocrine, vascular,
neoplastic, collagen/immuno
ABD PAIN: location & meal-relation
AGGRAVATING & ALLEVIATING FACTORS:
diet, over-the couter / prescrition drugs;
stress
SEVERITY?
· FREQUENCY? The easiest feature for
patient, but do not correlate with severity
· STOOL VOLUME? difficult for patient
· INDIRECT MEASURES are:
· Dry mouth
· Increased thirst
· Decreased urine output
· Weakness

Diarrhea Severity: Dehydration

Diarrhea severity: Dehydration
Clinical
Observation
Skin Turgor/
Capillary Refill
Peripheral
Pulses
Urine Output
Patient appears
well, thirst has
subsided
Skin recovers its
shape normally
Pulse is strong
Normal passing
of urine
Mild
Dehydration
Restlessness and
irritability; dry
mouth and tongue,
increased thirst
Skin recovers
its normal shape
slowly when
pinched
Pulse may be
slightly weak
or strong
Reduced urine
output
Moderate
Dehydration
Lethargy or
unconsciousness;
very dry mouth
and tongue
Skin recovers shape
very slowly when
pinched ("tenting")
Weak or absent
pulse
Minimal or no
urine
Severe
Dehydration

Oral Rehydration Solution (ORS)

Oral Reydration Solution (ORS)
home-made pedialyte
Rehydration Therapy3,6
Mild to
Moderate
Dehydration
Rehydration therapy with ORS must be administered
as soon as possible and frequently until the patient stabilizes
The WHO recommends ORS preparations with
a balanced glucose and electrolyte composition.
Ringer's lactate IV fluid
Or Normal saline or Dextrose solution
Severe
Dehydration
or Shock
(200 ml/kg or more of intravenous fluids during
the first 24 hours of treatment)
World Health
Organization
Sodium
chloride
2.6 gms/litre
Glucose,
anhydrous
13.5 gms/litre
Potassium
chloride
1.5 gms/litre
Trisodium
citrate,
dihydrate
2.9 gms/litre
2 c (0.47 L)
of Chicken
or Beef Broth
2 tbsp (25 g)
of Sugar
2 tbsp (25 g)
of Sugar
Chicken
Broth
LOW SODIUM
BONE
BROTH
CLASSIC BEEF
2 c (0.47 L)
of Water
1/2 tsp (3 g)
of Salt
wik
wiki How
-Recommended
ORS Composition6
4 1/4 c (1.0L)
of Water

Acute Diarrhea: Duration and Approach

Diarrhea duration: acute (<4wks)
mostly infective
· 40-70%: infective in older children & adults
- Norwalk & Norwalk-like : the most common in young children & infants in USA
· Spread person-to-person, food or water
· Incubation 12-48 hrs
- Rotavirus in children <2 yrs
- Bacterial typically severe
- most <1wk in immunocompetent pts hosts
- in immunocompromised: frequent and serious
· 30%: dietary, allergic or pharmacologic

Acute Diarrhea: Treatment Approach

Acute Diarrhea: Approach
1.
DIAGNOSTIC INVESTIGATION: RESERVED FOR
- PTS WITH SEVERE DEHYDRATION OR ILLNESS, persistent fever, bloody stool (Dysenteria), or immunosuppression
- cases of SUSPECTED NOSOCOMIAL INFECTION OR OUTBREAK. COMMUNITY-acquired diarrhea is viral.
2.
Treatment: focused on PREVENTING AND TREATING DEHYDRATION
3.
ORAL REHYDRATION THERAPY WITH EARLY REFEEDING is the preferred treatment
4.
ANTIMOTILITY AGENTS (LOPERAMIDE): avoided in severe diarrhea (fever >38℃, bloody,
disentery), but improve symptoms in mild & moderate conditions
5.
ANTIBIOTICS: effective for shigellosis, campylobacteriosis, Clostridium difficile, traveler's
diarrhea, and protozoal infections (when used appropriately)
6.
Probiotics: NOT recommended; except in cases of post-antibiotic-associated illness
7.
Prevention: adequate hand washing, safe food preparation, access to clean water, and
vaccination

Empiric Therapy for Acute Diarrhea in Adults

Approach to empiric therapy and diagnostic-directed
management of the adult patient with acute diarrhea
(suspect infectious etiology)
Passage of ≥3 unformed stools in 24 h plus an enteric symptom (nausea, vomiting, abdominal pain/cramps, tenesmus, fecal
urgency, moderate to severe flatulence)
Oral fluid therapy: for all cases, hydrate through fluid and salt intake
Food: soups, broths, saltine crackers, broiled and baked foods
Watery diarrhea
Dysenteric diarrhea (passage of grossly bloody stools)
Mild illness*
Moderate-to-severe illness*
No or low-grade fever
(≤100°F)
Severe illness* with fever
(> 101ºF) in a single case
(not outbreak)
Travel-
associated
Non-travel-associated
Travel
vs non-travel
association
Antibiotic
therapy
(Table 4)
No or
low grade
fever
(≤100°F)
Fever
(≥101°F)
*Illness severity:
Severe-total
disability due to
diarrhea; Moderate
= able to function
but with forced
change in activities
due to illness;
Mild = no change
in activities
Consider
≤48 h of
loperamide
therapy
<72 h
duration
≥72 h
duration
Consider
microbiologic
assessment
Empiric
treatment,
Azithromycin
1 mg in single
dose OR 500 mg
once daily
for 3 days
STEC: Shigatoxin E.coli =
severe hemorragic colitis+ hemolitic uremic syndrome
Persistent diarrhea (14 - 30 days) should be worked up by culture and/or culture-independent microbiologic
assessment, then treatment with anti-microbial agent directed to cause
Severity
Hydration
only, may use
loperamide 4 mg
initially to
control
stooling
Non-travel-
associated
Travel-
associated
Microbiologic assessment,
then anti-microbial agent
directed to cause for all but
STEC infection