Definition
A.Diarrhea is characterized by an abnormally high fluid content in the stool. Generally, diarrhea also involves an increase in the frequency of bowel movements (BMs), which can range from four to five to more than 20 times a day. Diarrhea may be an acute onset or chronic/persistent diarrhea.
B.Acute diarrhea is usually self-limited; the most common complication of diarrhea is dehydration and malabsorption.
C.Chronic diarrhea is defined as lasting longer than 14 days.
Incidence
A.The incidence of diarrhea is unknown.
B.The incidence of Clostridioides difficile infection is approximately 7%, and 28% of patients who were hospitalized have positive cultures for the organism. C. difficile–associated diarrhea has a mortality rate as high as 25% in the frail elderly.
C.Be aware that C. difficile can occur among patients in the community who have been treated with antibiotic therapy or antineoplastic agents with antibacterial activity.
Pathogenesis
A.The increased water content in diarrhea stools is due to an imbalance in the physiology of the small and large intestinal processes. See Table 14.7 for organisms that cause diarrhea.
TABLE 14.7 Organisms That Cause Diarrhea
Predisposing Factors
A.Enteric infections.
B.Females have a higher incidence of Campylobacter species infections.
C.Institutional: Day care and skilled nursing facilities.
D.Food: Raw or contaminated food.
E.Contaminated water or inadequate chlorinated water supply.
F.Travel.
G.Chemotherapy or radiation induced.
H.Vitamin deficiencies (niacin and folate).
I.Vitamin toxicity (C, niacin, and vitamin B3).
J.Ingestion of heavy metals (copper, tin, or zinc) or toxins.
K.Ingestion of plants, mistletoe, or mushrooms.
L.Antibiotics.
M.Immunodeficiency.
Common Complaints
A.Frequent watery stool.
B.Foul-smelling stools (fat malabsorption).
C.Flatulence.
D.Abdominal cramping.
Other Signs and Symptoms
A.Lethargy.
B.Fever.
C.Nausea and vomiting.
D.Currant jelly stool (blood and mucus).
E.Anorexia.
F.Dehydration in adults:
1.Thirst.
2.Less frequent urination.
3.Dark urine.
4.Dry skin.
5.Fatigue.
6.Dizziness.
7.Lightheadedness.
Subjective Data
A.Review the onset of diarrhea stools. What is the normal stool pattern?
B.Review the consistency, color, volume, and frequency of the stools.
C.Review dietary intake of raw foods, contaminated food, and nonabsorbable sugars, including lactulose or lactose in lactose malabsorbers. Review the use of artificial sweeteners such as sorbitol.
D.Review any contact with others who may have the same symptoms.
E.Have any of the stools contained blood?
F.Review travel history, including camping vacations.
G.Review medication history, including vitamins, herbal production, laxatives, antacids that contain magnesium, opiate withdrawal, Olestra, and methylxanthines (caffeine, theobromine, and theophylline):
1.Specifically inquire about the use of antibiotics in the previous 2 to 3 months (C. difficile may develop as late as 10 weeks after stopping antibiotics).
H.Review any food allergies and history of lactose intolerance.
I.Evaluate the presence of other symptoms such as fever and abdominal pain.
Physical Examination
A.Check temperature, pulse, respirations, blood pressure (BP; standing and sitting), and weight.
B.Inspect:
1.Observe the patient’s general overall appearance, the presence of lethargy or depressed
consciousness, or grimace during exam.
2.Evaluate muscle tone, skin turgor, reduced muscle, and fat mass.
3.Examine mouth, lips, and mucous membranes for signs, symptoms, and severity of dehydration.
4.Perianal examination for skin breakdown, erythema, and fissures.
C.Auscultation:
1.Assess heart and lungs.
2.Auscultate the abdomen in all four quadrants.
3.Assess the presence of borborygmi (significant increase in peristaltic action that may be audible and/or palpable).
D.Percuss abdomen.
E.Palpate:
1.Palpate the abdomen for masses, guarding, rebound tenderness, and peritoneal signs.
2.Palpate for lymphadenopathy.
3.Perform a rectal examination, including testing of stool for occult blood.
Diagnostic Tests
A.Stool specimens for evaluation of the following:
1.C. difficile: Reserved for patients having more than three loose stools per 24 hour and/or with risk factors including recent hospitalization, use of antibiotics, or advanced age:
a.Enzyme immunolinked assay (EIA) tests: Glutamate dehydrogenase (GDH) antigen and toxin detection, which detects toxin A, toxin B, or both.
b.Nucleic acid amplification test (NAAT): PCR test that detects presence of pathogenic strain of C. difficile.
2.Fecal leukocytes.
3.Blood tests:
a.Complete blood count (CBC): White blood cells (WBCs) may be elevated.
b.Electrolytes.
c.Albumin.
4.Bacterial culture.
5.Ova and parasites.
6.Giardia antigen.
7.Fecal calprotectin—indicates colonic inflammation.
8.Fecal alpha-1 antitrypsin levels—useful in chronic diarrhea.
9.Specific lab requests must be made to identify Campylobacter, Aeromonas, and Yersinia. Listeria should be suspected with outbreaks of nonbloody, febrile diarrhea in the setting of negative stool testing.
B.A colonoscopy for intestinal biopsy for chronic or protracted diarrhea or patients with AIDS should be done. A sigmoidoscopy alone may not reveal any abnormality.
C.Abdominal ultrasound to identify intussusception.
D.Abdominal CT.
E.Hydrogen breath test for lactose/fructose intolerance.
Differential Diagnoses
A.Diarrhea: Infectious etiology.
B.Inflammatory bowel disease (IBD):
1.Crohn’s disease (CD).
2.Ulcerative colitis (UC).
C.Cystic fibrosis (CF).
D.Giardiasis.
E.Protozoan.
F.Malabsorption syndromes.
G.Intussusception.
H.Stool impaction.
I.Irritable bowel syndrome (IBS).
J.Meckel’s diverticulum.
K.Intolerance to lactose, carbohydrates, and protein.
L.Antibiotic-associated diarrhea.
M.Pseudomembranous colitis.
N.Toxic megacolon.
O.Appendicitis.
P.Celiac disease.
Plan
A. 
See Section III: Patient Teaching Guide Diarrhea.
B.Examination of stools for ova and parasites should be done every other day or every 3 days.
C.Rehydration with oral fluids for each diarrhea stool. Administer small amounts at frequent intervals. Solution should contain water, salt, and sugar. Diluted fruit juices or flavored soft drinks, broths, or soups should be sufficient with mild cases of diarrhea. Gatorade type solutions may be sufficient for mild cases, but for more severe cases oral rehydration solution (Rehydralyte or Ceralyte) should be considered. Intravenous (IV) fluids should be used for severe hypovolumemia.
D.Hold foods until hydration is completed. Dietary modifications are poorly validated in studies; however, the use of saltine crackers, boiled vegetables or starches, and bananas is generally supported in patients with nausea, vomiting, or anorexia.
E.Use antibiotics (or the discontinuation of antibiotics in the case of C. difficile) or antiparasitic agents, depending on the etiology. Empiric use of antibiotics is not recommended as most cases of diarrhea are viral. However, in cases of severe and/or bloody diarrhea, especially with fever, the benefit of the antibiotic likely outweighs the risk.
F.The use of probiotics, Lactobacillus GG (I, A) and Saccharomyces boulardii (II, B), has been found to be effective in repopulating or maintaining the colonic gut flora. They may reduce the spread of rotavirus.
G.Encourage proper hygiene and food preparation to prevent spread and future infections.
H.Water should be boiled for at least 1 minute if contamination is suspected.
I.Antiprotozal: Nitazoxande (Alinia) 500 mg every 12 hours for 3 days.
J.HIV/AIDS: Crofelemer (Fulyzaq) for noninfectious diarrhea in adults on antiretroviral therapy; 125 mg tablet twice per day.
K.Antidiarrheals.
1.Loperamide (Imodium):
a.Initially 4 mg, then 2 mg after each loose stool. Maximum dose 16 mg/d. Stop in 48 hours if diarrhea is not relieved.
b.Chronic diarrhea: Initially 4 mg, maintenance 4 to 8 mg/d; reevaluate if no improvement in diarrhea in 10 days at 16 mg/d.
2.Bismuth subsalicylate (Kaopectate) 262 mg/15 mL, take 30 mL every 30 to 60 minutes if needed; maximum four doses per day. Slower onset of action compared to loperamide; however, more useful in patients with fever and dysentery.
3.Diphenoxylate HCL (Lomotil) two tablets or 10 mL four times daily until diarrhea is controlled; maintenance, two tablets or 10 mL per day. Increased risk of cholinergic side effects.
L.C. difficile treatment:
1.Stop antibiotics.
2.Avoid antiperistaltic agents.
3.Initial occurrence:
a.Vancomycin 125 mg four times daily for10 days OR
b.Fidaxomicin (Dificid) 200 mg orally twice a day for 10 days OR