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45 Cards in this Set
- Front
- Back
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Diarrhea
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More than three loose or unformed bowel movements
Abnormal increase in stool weight |
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What is the leading cause of death in children under the age of 4?
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Diarrhea
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Etiology of acute diarrhea
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Less than 14 days
Self-limited - Caused by drugs, food poisoning or infections |
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Etiology of non-inflammatory diarrhea
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Watery, non-bloody
Toxin-producing bacteria/Giardia: Periumbilical cramps, nausea, vomiting, bloating Viral enteritis/ S. Aureus: prominent vomiting Small bowel=large volume |
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Etiology of inflammatory diarrhea
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Fever, bloody diarrhea (dysentery)
Colonic tissue damage: invasion or toxin Usually smaller volume, fecal leukocytes |
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Diagnosis of diarrhea
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Distinguish mild from severe
History - onset, duration, frequency, severity, rectal urgency, recent travel, drugs (Abx), food, water Fluid, hydration and mental status Abd/Rectal/FOBT important |
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Causes of diarrhea in geriatrics
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Watery diarrhea with chronic constipation may be fecal impaction or obstructing neoplasm.
Very small amounts leaking around impaction. |
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Pathophysiology of osmotic diarrhea
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Absorption of water in intestines dependent on adequate absorption of solutes. If solutes stay in lumen, water does also, causing diarrhea.
Typically results from two situations: - Ingestion of poorly absorbed substrate - common examples: mannitol or sorbitol, epson salt (MgSO4) and some antacids (MgOH2) - Malabsorption - Inability to absorb certain carbohydrates is the most common deficit e.g. deficiency in lactase - lactose intolerance - lactase stays in lumen drawing out water - lactose fermented by colonic bacteria - excessive gas Stops after the patient is NPO except water or stops consuming the poorly absorbed solute. |
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Pathophysiology of secretory diarrhea
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Results when secretion is greater than absorption.
Large volumes of water are normally secreted into the small intestinal lumen, but most is efficiently absorbed before reaching the large intestine. Diarrhea occurs when secretion of water into the intestinal lumen exceeds absorption. Bacterial Toxins: - Many millions of people have died of the secretory diarrhea associated with cholera. Vibrio cholerae, produces cholera toxin, which strongly activates the cascade that opens the chloride channels instrumental in the secretion of water from the intestinal wall - uncontrolled secretion of water into lumen. People die from large water volume loss. Other bacterial toxins (E. coli) have similar effects. Can be lethal if not aggressively treated to maintain hydration. |
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Pathophysiology of diarrhea caused by other agents
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Some laxatives
- Ex: senna, diocytl sodium sulfosuccinate Hormones secreted by certain types of tumors - Ex: vasoactive intestinal peptide, serotonin, calcitonin, prostaglandin E1 Broad range of drugs - Ex: some types of asthma medications, antidepressants, cardiac drugs Certain metals, organic toxins, and plant products - Ex: arsenic, insecticides, mushroom toxins, caffeine In most cases, secretory diarrheas will not resolve during a 2-3 day fast. |
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Altered intestinal motility
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Efficient absorption requires large surface area and slow enough passage to allow maximal contact with mucosal epithelium.
Increased activity may reduce the surface area and limit the contact time for nutrient absorption diarrhea. Long-distance runners(DynaMed) Hyperthyroidism |
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Risk factors for diarrhea
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Special concern in older adults
- majority of deaths associated with diarrhea in U.S. Attend day care or provide day care, nursing home International travel Immunocompromised patients - AIDS, chemotherapy Diet - exposure to contaminated foods/water, some “diet” foods Lactase deficiency - very common in African and Asian people Meds - Antibiotics, Metformin, H2 Antagonists, PPIs, β-blockers, antacids, laxatives Acute diarrheal illness common in first 100 days after allogeneic bone marrow or peripheral stem cell transplantation. |
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Inflammatory and infectious diarrhea
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The epithelium of the digestive tube is protected from insult by a number of mechanisms, disruption of the epithelium due to microbial or viral pathogens is a common cause of diarrhea in all species.
Inflammation and ulceration of the mucosa often result in the release of mucus, serum proteins and blood into the lumen - osmotic release of water Destruction of absorptive epithelium - impairment of water absorption Defensive secretions from leukocytes can further damage intestinal epithelium Presumed cause of diarrhea in ulcerative colitis Others: see infectious etiologies above. |
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Possible underlying causes of diarrhea
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Diabetes, IBS, IBD, colon cancer, Crohn's
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What is the hallmark of small bowel diarrhea?
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Watery, non-bloody stool
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What is the hallmark of large bowel diarrhea?
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Blood or mucus present in the stool
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Signs of dehydration
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Capillary refill
Decreased skin turgor Dry mucus membranes Hypotension Decreased urination Pediatrics - absence of tears when crying - irritable/lethargic - depressed fontanelles - dry diapers |
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What are some possible general physical findings of diarrhea?
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Fever suggests IBD or infection
Ammonia or urinary breath odor suggests renal failure Tremor suggests hyperthyroidism Lymphadenopathy in cancer or TB |
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What are some possible abdominal physical findings of diarrhea?
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Masses
RLQ mass - Crohn’s Dz, appendicitis, pelvic abscess Recent surgery/scars |
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Differential diagnosis of diarrhea
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Pseudomembranous colitis
Diverticulitis Spastic (irritable) colon Fecal impaction Malabsorption Appendicitis Zollinger-Ellison Syndrome --- duodenal gastrinoma in 15-20% Ischemic bowel Patient desire to lose weight - possible laxative abuse Alternating with constipation or increased mucus suggests IBS Nocturnal diarrhea in diabetic neuropathy Dietary history includes dairy, especially milk- possible Lactose Intolerance |
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Lab findings of diarrhea
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Only consider if diarrhea is prolonged
CBC w/diff ↑ WBC = infection; ↓Hgb/Hct = anemia from blood loss BMP if dehydration suspected - Serum electrolytes ↑ Na = dehydration; ↓ K = excess loss in stool (potential cardiac arrhythmias) - Blood urea nitrogen, creatinine ↑ in dehydration |
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Stool sample findings of diarrhea
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Occult Blood
- IBD, bowel ischemia, bacterial infections Fecal leukocytes - Salmonella, Campylobacter, Yersinia Stool ova and parasites (O & P) Routine Stool Culture - Salmonella, Shigella, Campylobacter, E. coli O157:H7 - if community-acquired or traveler’s diarrhea >1 day or accompanied by fever or bloody stools Culture for C. Difficile toxins if recent hospitalization or antibiotics Fecal antigen detection testing for Giardia may be more sensitive and specific than O&P Modified acid-fast (Ziehl-Neelson) stain if immunocompromised - Cryptosporidium |
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When should labs be ordered and what should be ordered?
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Worsening or persists for >7 days, send for stool analysis
- Fecal leukocytes or lactoferrin - Ovum / parasite - Bacterial culture |
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Complications of diarrhea
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Fluid loss leads to:
- Dehydration can lead to shock - Electrolyte losses (Na, K, Mg, Cl) - Vascular collapse Malnutrition Sepsis Anemia HCO3 loss could cause metabolic acidosis High risk of complications with Cholera, very young or very old, debilitated. |
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Treatment/management of diarrhea
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Severe diarrhea - rehydration, electrolyte replacement, Pedialyte
- Fluid containing NaCl, KCl and glucose - Parenteral/enteral - Early refeeding NO straight sports drinks! - Too much sugar can make it worse. For severe cases, consider NG rehydration in infants or Lactated Ringers. Study - diarrhea lasted half as long as infants on IV rehydration. |
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AAFP rehydration recommendations
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Gatorade 500 cc, water 500 cc, and salt 1/2 teaspoon
Water 1 quart, baking soda 3/4 tsp, salt 1/4 tsp, and 2 bananas pureed |
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UNICEF/WHO rehydration recommendations
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1 L clean drinking water, 8 level tsp of table sugar (sucrose), 1 level tsp of table salt
To add Potassium and improve taste add ½ cup of orange juice OR ½ banana mashed. |
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BRAT diet
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Bananas
Rice Applesauce Toast Easy on gut, minimal on nutrients |
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Pediatric dietary recommendations
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Early refeeding is encouraged
- one day Pedialyte, then back to regular diet Infants - Breastfeeding preferred - Formula-fed - small, frequent feedings - Fiber-supplemented formula - infants > 6 months |
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Adult dietary recommendations
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o recommend starting with clear soup with rice, salted crackers, dry toast or bread, and sherbet
o as frequency reduces, slowly add simple foods like baked potato, chicken noodle soup o as stool retains shape, add baked fish, poultry, applesauce, bananas • Try to remove offending agent. • During active diarrhea AVOID coffee/caffeinated soda, alcohol, dairy products, most fruits, vegetables, red meats, fatty foods, and heavily seasoned foods. |
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OTC medications for diarrhea
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Loperamide (Imodium)
- 4 mg initially, 2 mg after each loose stool (max. 16g/24h) - Possible SE: nausea, abdominal cramps, dizziness, toxic megacolon, paralytic ileus, angioedema, anaphylaxis Bismuth subsalicylate (Pepto-Bismol, Kaopectate) - 2 tabs or 30 ml q 1H (max. 4200 mg/24h) ---traveler’s diarrhea - SE: blackened stools/tongue, tinnitus --- Adult Pepto should NOT be used for kids because of subsalicylate Antidiarrheals should not be used in bloody diarrhea of unknown cause. Need to rid body of any infectious agents. |
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Medications for infectious diarrhea
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Diarrhea is body’s natural defense
- Caution advised with antiperistaltic agents like diphenoxylate and loperamide ↑ risk of toxic megacolon Antibiotic indicated when: - Diarrhea persists for > 48 hours - Passes six or more stools in 24 hours - Associated with fever, blood or pus in the stools |
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Probiotic therapy
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Meta-analysis of 23 randomized trials showed reduced duration of acute infectious diarrhea and ABx-associated diarrhea
- Lactobacillus casei subspecies rhamnosus GG (Dicoflor 60) twice daily for 5 days - Mixture of L. delbrueckii var bulgaricus, L. acidophilus, Streptococcus thermophilus and B. bifidum (Lactogermina) twice daily for 5 days |
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Zinc therapy
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Supplementation in children appears to reduce duration and severity of diarrhea, but may increase vomiting.
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Diarrhea medications for immunocompromised patients
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Generally refractory to conventional therapy
May respond to opium tincture when loperamide not successful Unusual opportunistic infections Antibiotic may be option |
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Factitious diarrhea
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Due to the intentional overuse of laxatives.
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Etiology of chronic diarrhea in adults
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Secretory diarrhea
- idiopathic, laxative abuse, irritable bowel syndrome, diabetes mellitus, fecal incontinence Malabsorption - pancreatic disease, noninflammatory short bowel syndrome, postgastrectomy, hyperthyroidism, cholestasis, cystic fibrosis Microscopic colitis Inflammatory bowel disease Celiac disease Radiation colitis |
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Tenesmus
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Urge to defecate even though a patient just used the restroom.
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Infectious causes of chronic diarrhea
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Giardiasis
Amebiasis Cyclospora Whipple's disease Intestinal capillariasis |
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Rome criteria for IBS
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???
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Flatus
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Gas
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Differential diagnosis of chronic diarrhea
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Whipple disease
Abetalipoproteinemia Dietary products in children (e.g. apple juice) |
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Treatment/management of chronic diarrhea
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Diarrhea is a symptom - treat underlying condition!
Consider urology referral |
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Patient education for chronic diarrhea
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Help patient understand bowel physiology and that normal frequency varies widely.
Drink fluids Dietary consult when appropriate Restrict colon stimulants - gluten products, sorbitol, lactose-containing products, food allergens |
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Medications for chronic diarrhea
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Variable from a short and treatable course (factitious and altered motility), to a chronic illness (e.g. Crohn disease, ulcerative colitis).
Opiates (includes Lomotil) - Effective but can be addictive Loperamide (Imodium) - 4 mg initially, 2 mg after ea stool (max. 16 mg/24h) Diphenoxylate-atropine (Lomotil) - 1 tab tid-qid prn Clonidine - 0.1-0.6 mg PO bid, patch 0.1-0.2 mg/d - alpha-2 Adrenergic agonist inhibit intestinal electrolyte excretion) Octreotide (Sandostatin) |
