GASTROENTERITIS

GASTROENTERITIS (gastro/gastric flu; stomach flu)

·         Inflammation of the gastrointestinal tract both the stomach & small intestines which leads to acute diarrhea.

·         Caused by infection, viruses, bacteria, parasites (protozoa, helminths) or adverse reaction to medications.

·         Most cases are seen during winter in the temperate climates & summer in the tropics.

Disease & Organism	Pathogenesis	Manifestations	Management
Selected Bacterial Infections of the Bowel
Traveler’s diarrhea: Escherichia coli Incubation: (24-72 hours)	Enterotoxin causes hypersecretion of the small intestines	Abrupt onset of diarrhea; vomiting rare	Prophylactic bismuth subsalicylate; antidiarrheals such as loperamide or diphenoxylate; 3-5 day course of norfloxacin, ciprofloxacin, or trimethoprim-sulfamethazole
Staphylococcal Food poisoning Incubation: (2-8 hours)	Enterotoxin impairs intestinal absorption & affects vomiting centers in the brain	Severe nausea, vomiting; abdominal cramping, diarrhea; headache and fever	Fluid and electrolyte replacement as needed
Botulism: Clostridium botulinum Incubation: (1.5-8 days)	Absorbed enterotoxin produces neuromuscular blockade and progressive paralysis	Diplopia, pupils fixed & dilated; dry mouth, dysphagia; progressive cephalocaudal weakness & paralysis; GI symptoms minimal	Gastric lavage to remove toxin from gut; administration botulinus antitoxin; respiratory, fluid and nutritional support
Cholera Vibrio Cholerae Incubation: (1-3 days)	Enterotoxin affects entire small intestine, causing secretion of water & electrolytes into bowel lumen	Severe diarrhea with “rice watery stool”, grey, cloudy, odorless, with no blood or pus; vomiting; thirst; oliguria, muscle cramps, weakness; dehydration	Oral or intravenous rehydration; possible antimicrobial therapy with ampicillin, tetracycline, trimethoprimsulfame-thoxazole, others
Hemorrhagic colitis:  E. coli Incubation: (1-3 days )	Enterotoxin causes direct mucosal damage in large intestine; also toxic to vascular endothelial cells	Severe abdominal cramping, watery diarrhea that becomes grossly bloody; fever	Supportive care with fluid replacement and bland diet; may require dialysis or plasmapheresis for complications
Salmonellosis: Salmonella Incubation: (8-48 hours)	Superficial infection of the GI tract without invasion or production of toxins	Diarrhea with abdominal cramping, nausea, vomiting; low-grade fever, chills, weakness	Treatment of symptoms: trimetho-primsulfamethoxazole, ampicillin, or cipro- floxacin for severe illness

Shigellosis (bacillary dysentery): Shigella Incubation: (1-4 days)	Local tissue invasion, primarily involving large intestine and distal ileum; endotoxin causes fluid and electrolyte secretion into bowel lumen	Watery diarrhea with severe abdominal cramping and tenesmus; lethargy	Fluid and electrolyte replacement; correction of acidosis; antibiotic therapy
Protozoal Infections of the  Bowel
Giadiasis: Giardia lamblia Incubation: (1-3 weeks or more)	Throphozite attaches to the mucosa in duodenum and jejunum, causing superficial invasion, inflammation, tissue destruction	Diarrhea, mild or severe, daily or intermittent; anorexia, nausea, vomiting;epigastric  pain, cramping, distention; flatulence, belching; may be asymptomatic	Metronidazole, quinacrine, furazolidone
Amebiasis: Entamoeba histolytica Incubation: (2-4 weeks)	Organisms may reside in large intestine w/o causing disease or can invade colon wall, causing ulceration; may be carried via blood à liver à abscess	Usually asymptomatic; diarrhea may be mild, with few semiformed mucus containing stools per day, or severe, with 10-20 blood streaked liquid stools/day; abdominal cramps; colic, tenesmus, vomiting, tenderness; weight loss, fatigue	Metronidazole, Diloxanide furoate or iodoquinol; chloroquine for hepatic abscess
Cryptospo-ridiosis: Crypto- sporidium Incubation: (2-10 days)	Organisms attach to epithelial surface of small bowel(jejunum), causing villous atrophy and mild inflammatory changes	Asymptomatic to profuse, watery diarrhea of sudden onset, abdominal cramping; malaise, fever; anorexia, nausea, vomiting; electrolyte imbalance; weight loss	Self-limiting in immunocompetent clients. For immuno-deficient: spiramycin, zidovudine(AZT), paromomycin (Humatin), octreotide, eflornithine; fluid & electrolyte imbalance; parenteral nutrition
Selected Helminthic  Disease
Nematode Infections (Ascaris, pinworm, hookworm, trichinosis)	Eggs are ingested in fecally contaminated food, under- cooked meats; it may enter through skin or by ingestion	Low-grade fever,cough,epigastric pain , vomiting, abdominal distention, nocturnal perianal, perineal pruritus, pruritic dermatitis, diarrhea, anorexia	Helminthic infections often treated with single oral dose or 3-day course of pyrantel pamoate (Antiminth®) or mebendazole (Vermox®); Corticosteroids to reduce inflammation & manage symptoms
Cestode infections (Intestinal fluke; tapeworms)	Organism is ingested by eating uncooked fish/meat, fecal contamination; swallowing infected hosts	Asymptomatic; diarrhea; abdominal pain; nausea, vomiting; thrombocytopenia, anorexia, weight loss, irritability

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Signs & Symptoms: (Gastroenteritis)

ü  Anorexia

ü  Nausea & vomiting

ü  Orthostatic hypotension

ü  Fever

ü  Headache

ü  Loss of appetite

ü  Abdominal cramping & pain

ü  Borborygmi

ü  Increased bowel sounds

ü  Bloody stools

ü  Diarrhea

ü  Poor skin turgor

ü  Fatigue & weakness

Screening & Diagnosis:

·         Stool culture – reveals (+) organism that causes  infection, presence of WBC, blood, mucus in the stool

·         Complete blood count - ↑ hemoglobin & hematocrit related to presence of vomiting & diarrhea.

·         Kidney function test - ↑ creatinine & BUN

Treatment:

·         Hydration & electrolyte balance

·         Diet therapy– bland foods, avoid foods high in simple sugars because the osmotic load will worsen diarrhea.

·         Probiotics – to restore beneficial bacteria to the body. (e.g. yogurt, kimchee, sauerkraut, & kombucha)

·         Medications

o    Antibiotics: metronidazole,vancomycin, fluoroquinolone

o    Antidiarrheals: loperamide

o    Antihelmithic /antiparasitic: pyrantel pamoate (Antiminth®), mebendezole (Vermox®), iodoquinol (Amebaquine®), paromomycin (Humatin®)

o    Antiemetic: promethazine (Phenergan®)

Complications:

·         Dehydration

·         Malabsorption

Nursing Interventions:

·         Rest bowel (NPO) for 24 hrs. before starting diet.

·         Administer prescribed medications.

·         Stress the importance of the following:

o    Oral rehydration

o    Proper handwashing, particularly before handling food, and after each bowel movement.

o    The need to wash contaminated clothing and linens separately in hot water and detergent.

o    Safe food storage, handling, and preparation.

o    Keeping toilet areas clean and maintain good personal hygiene.

·         Monitor for signs & symptoms for possible complications.