Ch. 16 - Diarrhea

Question 1

Diarrhea

Answer 1

• Abnormal increase in stool frequency, liquidity, or weight
• > 3 bowel movements per day considered abnormal
• Acute: <14 days, manage with fluids and electrolytes replacement, dietary intervention, and non-Rx drugs
• Persistent: 14 days - 4 weeks; Chronic: > 4 weeks
• These are secondary to a condition and need medical intervention
• Causes 1.9 million death per year in kids <5 y.o.
• ~179 million bases of acute gastroenteritis yearly
• Highest prevalence in kids <5 y.o., lowest in older adults

Question 2

Diarrhea Pathophysiology

Answer 2

• Attendance/employment at daycare centers, food handlers, caregivers, congregate living conditions, eating unsafe foods, presence of medical conditions (AIDS or diverticulitis) all increase diarrhea
• Can also be caused by poisoning, medications, intolerance of certain foods, or various non-GI acute or chronic illnesses

Question 3

Viral Gastroenteritis

Answer 3

• Norovirus - most common cause in adults and second most common in kids
• Often transmitted by contaminated foods but can also be by person-person contact or via contaminated surfaces
• Rotavirus causes most severe gastroenteritis before vaccines, seasonal infection peaking November-February
• Spread by fecal-oral route, can cause severe dehydration and electrolyte disturbances resulting in death
• Less common causes: adenovirus, astrovirus, and hepatitis A virus

Question 4

Bacterial Gastroenteritis

Answer 4

• Bacteria causes ~10% of acute diarrheal illnesses each year, usually food borne
• Campylobacter spp., Salmonella spp., Shigella spp., E. Scherichia coli, enterotoxigenic E. Coli, DAEC, Staph, Clostridium, Yersinia, Bacillus cereus (in order of decreasing likelihood of causality)
• Cause diarrhea through elaboration of enterotoxin attachment and production of local inflammatory changes in gut, or by invading mucosal epithelial cells
• Toxin produced: watery diarrhea, involves small intestine
• Invasive organism: dysentery-like diarrhea (bloody) with fever, cramps, straining, and frequency small stools
• Enteric infection: prolonged bowel dysfunction including IBS (abdominal pain and discomfort)
• IBS develops in 2-30% of patients with gastroenteritis
• May also unmask underlying chronic conditions like celiac disease, Crohn’s, and ulcerative colitus

Question 5

Protozoal Diarrhea

Answer 5

• Giardia lamblia, Entamoeba histolytica, Isospora belli, and Cryptosporidium spp.
• Can’t self-treat, need Rx treatment

Question 6

Food-Borne Gastroenteritis

Answer 6

• Causes ~47.8 million acute gastroenteritis episodes
• 59% by virus, 39% by bacteria, and 2% by protozoa
• Salmonella and campylobacter most common bacterial pathogens
• Traced to poor sanitation, poor manufacturing practices, and contamination of foods
• Specific foods can also increase infections, so question about food intake 48-72 hours before onset
• Illness by E. Coli O157:H7 and other STECs are a major health issue; toxins by these organisms cause acute bloody diarrhea
• Can lead to fatal complications like hemolytic uremic syndrome or thrombotic thombocytopenic purpura

Question 7

Traveler’s Diarrhea

Answer 7

• Acute, secondary diarrhea from ingesting contaminated food or water
• Usually caused by bacterial enteropathogens
• ETEC found in 50-76% of traveler’s with diarrhea
• Found often in fruits, vegetables, raw meat, seafood, and even hot sauces (less commonly water/ice cubes)
• ETEC produce 2 plasmid mediated enterotoxins that closely resemble cholera toxin
• Other organisms may cause diarrhea by entero of cytotoxins
• Experience 3-8+ watery stools each day, usually subsides in 3-5 days

Question 8

Food-Induced Diarrhea

Answer 8

• Diarrhea from food allergies or ingestion of excessively fatty, spicy, or high amounts of fiber/seeds
• If carbs aren’t hydrolyzed, they pool in lumen of intestine and promote osmotic imbalance by drawing fluid into lumen and causing diarrhea
• Temporary milk tolerance can occur from infectious diarrhea, use lactase enzyme products

Question 9

Diarrhea Clinical Presentation

Answer 9

• Medical history can usually determine cause, but may need lab tests in some cases
• Classifications: osmotic, secretory, inflammatory, or motor
• Osmotic and secretory cause acute diarrhea usually
• Inflammatory and motor cause chronic diarrhea
• Enterotoxins evoke the release of endogenous secretagogues that increase secretory reflexes, some by directly stimulating GI secretomotor neurons to increase secretion
• Inflammatory mediators can also be activated which can stimulate GI motility and cause urgent defecation
• Fluid and electrolyte imbalance is a major complication and causes the need to assess for dehydration; kids < 5 y.o. and adults >65 y.o. are at the greatest risk
• <2 y.o. most likely to require hospitalization form complications
• Severe dehydration = 10%< loss of body weight
• Increased likelihood of death in adults >65 y.o. form enteric infections

Question 10

Meaning of Poop Characteristics

Answer 10

• Undigested food particles - disease of small intestine
• Black, tarry stools - upper GI bleed
• Red stools - lower bowel or hemorrhoidal bleeding; or from eating red foods or drug induced
• Secretory diarrhea - high in sodium
• Small-volume stools- colonic disorder
• Yellow stools - bilirubin and serious liver pathology
• Whitish tint - fat malabsorbance disease

Question 11

Diarrhea Treatment Goals

Answer 11

1. Prevent or correct fluid/electrolyte loss and acid-base distribution
2. Control symptoms
3. Identify and treat the cause
4. Prevent acute morbidity and mortality

Question 12

Diarrhea General Treatment

Answer 12

• Often self-limiting
• Self-treat mild to moderate, uncomplicated diarrhea in kids and adults
• Focus on fluid replacement and dietary measures
• Can also use symptomatic control with non-Rx
• Normal function usually restored 24-72 hours without treatment
• Diarrhea in <6 mo. or moderate diarrhea in <2 y.o. need PCP or ER treatment
• Conditions that last >48 hours in adults need med. referral
• Blood/mucus stools, diabetes, CV disease, renal disease, chronic/unstable medical conditions, severe bowel pain, immunocompromised, preggo ==> PCP

Question 13

Diarrhea Nonpharmacologic - Fluid/Electrolyte Management

Answer 13

• Rehydration with ORS - preferred for mild to moderate diarrhea; equally effective to IV in mild-moderate diarrhea in kids
• Water follows ions, especially sodium
• Sodium-glucose cotransport mechanism not adversely affected by most diarrhea cases - use hypotonic ORS with low glucose concentration
• Rehydration over 3-4 hours replaces water/electrolyte deficits
• Maintenance: electrolyte solutions given to maintain normal body compositions
• If otherwise healthy, can just increase clear fluid intake
• Premixed solutions are preferred for kids
• Different organizations recommend different sodium concentrations in ORS
• Rehydration solutions: 70-90 mEq/L of sodium; maintenance: 45-50 mEq/L
• Cereal-based ORS good for kids with cholera
• Don’t use household oral solutions, can have too high of a carb or sodium content and make diarrhea worse
• Don’t use soda, tea, apple juice, chicken broth in <5 y.o.
• Sports drinks in 5 y.o.+ with bland carbs is okay

Question 14

Diarrhea Nonpharmacologic - Diet Management

Answer 14

• Early refeeding with maintenance hydration improves outcomes by decreasing diarrhea duration, stool output, and increasing weight gain
• Encourage reintroducing food as soon as rehydrated
• Don’t withhold food for more than 24 hours
• Don’t use BRAT diet, low in necessary nutrition, especially if used long term
• Avoid spicy foods and drinks with caffeine

Question 15

Diarrhea Preventative Measures

Answer 15

• Isolate individuals with diarrhea, washing hands, sterilize areas to reduce transmission in congregate homes
• Strict food handling, sanitation, and hygienic practices
• Short term BSS prophylaxis for traveler’s diarrhea (not enough evidence to support this)
• Prophylactic antibiotics only recommended for traveler’s at high risk

Question 16

Diarrhea Pharmacologic

Answer 16

• Symptom control with no harm when taken correctly
• Only BSS and loperamide shown to decrease stool frequency/duration
• No antidiarrheals shown to improve outcomes for <5 y.o.

Question 17

Diarrhea - Loperamide

Answer 17

• Popular, effective, antidiarrheal
• Synthetic opioid without CNS effects (effects P-gp)
• Stimulate peripheral micro-opioid receptors on intestinal circular muscles to slow motility
• Relief for acute, nonspecific diarrhea
• Decreases daily fecal volume, increases viscosity and bulk volume, decreases fluid/electrolyte loss
• Okay to use if afebrile, low fever, or non-blood stools
• Use in 6 y.o.+, mot recommended for 2-6 y.o. due to benefits:risk
• Also for traveler’s diarrhea and chronic IBS
• Off-label uses require medical supervision
• Few SE other than occasional dizziness and constipation
• Rare SE: abdominal pain/distension, N/V, dry mouth, fatigue, allergic reactions (D/C if any of these occur)
• Not recommended for invasive, bacterial or antibiotic-induced diarrhea
• Infection suspected? Medical referral
• Few DD interactions: metabolized by CYP3A4 and CYP2C8, so increased levels of loperamide may occur if taken with other drugs metabolized by said enzymes
• May significantly decrease saquinavir concentrations, don’t take together

Question 18

Diarrhea - BSS

Answer 18

• Effective for acute diarrhea
• 2 active moieties once digested
• Bismuth part acts as a antimicrobial
• Salicylate acts as an antisecretory
• Together they decrease the frequency of unformed stools, increase stool consistency, relieve cramping and decrease N/V
• Antisecretory good for traveler’s diarrhea
• Approved for 12 y.o.+
• Good for indigestion or as an adjunct to PUD
• Caution if also taking with aspirin, could lead to toxic levels of salicylate
• Mild tinnitus can occur with salicylate toxicity, D/C and see medical professional if this occurs
• Don’t use on children with viral infections (Reye’s Syndrome) or those with AIDS
• Don’t use if sensitized to aspirin or prone to gout attacks
• Use recommended doses to decrease SE and neurotoxicity
• Black tongue/stool can occur, will reverse once done taking medicine
• May interfere with radiographic intestinal studies
• Increased risk of toxicity when taken with warfarin, valproic acid, and methotrexate
• Probenecid is inhibited by the salicylate moiety and tetracycline/quinolones inhibited by bismuth (don’t use together)

Question 19

Diarrhea - Digestive Enzymes

Answer 19

Use lactase enzyme preparations with milk or dairy products to prevent osmotic diarrhea

Question 20

Diarrhea Product Selection Guidelines

Answer 20

-FDA final guidance on non-Rx liquid products with measuring devices (cups, syringes, spoons)

Key Points

1. Device must be included with oral liquid products
2. Calibrate device to recommended product directions
3. Only use device with that product
4. Visible markings even when liquid is inside

Question 21

Diarrhea Special Populations

Answer 21

• Children < 5 y.o.: rehydration with ORS ONLY, see PCP if diarrhea persists
• Elderly >65 y.o.: caution against self-treatment since at an increased risk that diarrhea could be severe/fatal
• None for preggo either, especially BSS (CI)
• Avoid BSS while BF too

Question 22

Diarrhea Preferences/Factors

Answer 22

• Choose based on etiology, symptoms, interactions, CIs

- Preference for dosage form or products with fewer doses should also be considered

Question 23

Diarrhea Complementary Therapies

Answer 23

• Probiotics may be effective in preventing and treating mild, acute, uncomplicated diarrhea (especially rotavirus in children)
• Not supported for moderate to severe diarrhea
• Safe in most patients, don’t use in elderly, critically ill, and immunocompromised (increased bowel disease risk)
• Not regulated by FDA so can’t claim to treat diarrhea
• Zinc supplements daily shown to decrease duration, severity, and persistence of acute diarrhea in kids <5 y.o.
• Mostly benefits kids with zinc deficit
• Zinc deficit: 10 mg per day in <6 mo., 20 mg per day for older infants and children for 10-14 days used with ORS
• SE: increased risk of vomiting
• Don’t recommend herbal or homeopathic products

Question 24

Diarrhea Assessment

Answer 24

-Assess symptoms and make clinical judgements
-Persistent/chronic diarrhea, high fever (>102.2) projectile vomiting, abdominal pain in >50 y.o., blood/mucus in stools are exclusions for self-treat
-No severe dehydration for self-treat either, assess for body weight loss to determine
-Get complete medication history first
If orthostatic hypotension with diarrhea occurs, see medical professional

Question 25

Diarrhea Counseling

Answer 25

- Dehydration MOST important to prevent - May need non-Rx drug to stop frequent bowel movements - Counsel on rehydration and idet - Proper use of ORS and diet management for kids - If choosing a powder ORS, give explicit instructions for mixing and ensure they understand them - Don't use tap water in developing countries Antidiarrheal Recommendations: 1. Review label instructions with patient or caregiver 2. Calculate appropriate dose based on patient weight/age, emphasize the max daily dose 3. DD interactions SE, CIs, max duration of treatment, and when to seek medical help should be included

Question 26

Diarrhea Evaluation

Answer 26

- Mild-moderate is generally self-limiting to 48 hours - Manage with rehydration, symptomatic drug therapy, and diet (monitor for dehydration - Medical referrals: high fever, worsening illness, blood/mucus stools, diarrhea >48 hours, or dehydration - Also refer infants, young kids, frail elderly, preggo, and patients with chronic illness due to increased risk of secondary complications