The document provides guidance on diagnosing and treating diarrhea. It describes how to assess patients by inquiring about symptoms, performing a physical exam including vital signs and stool sample analysis. Treatment involves rehydration and replacing lost fluids and electrolytes. For inflammatory diarrhea, antibiotics may be prescribed after testing stool for white blood cells. Mild cases often resolve with increased fluids, rest and over-the-counter medications to absorb water in the gut. Hospitalization is needed only for severe dehydration that cannot be managed orally.

1. Diarrhea
Presentation
Complaints may range from acute, copious diarrhea producing shock, to concern
because an occasional stool is not well formed. Typically, there is crampy pain
throughout the abdomen, especially before a diarrhea stool, and some irritation of
the anus. Tenesmus (the frequent urge to defecate) can exist without diarrhea.
What to do:
• Ask specifically about the frequency of stools, the volume (much liquid implies
a defect in absorption in the small bowel, while tenesmus producing little
more than mucus implies inflammation of the rectosigmoid wall), the
character (color, odor, blood, or mucus) and the consistency (like water or
just loose stool). Ask about travel, medications (including antibiotics), prior
similar symptoms, and nocturnal symptoms (rare with functional disease).
• Perform orthostatic vital signs and urinalysis and weigh pediatric patients. Any
symptoms fall in presssure, or pulse rise of more than 20 beats per minute
after standing for a minute suggests hypovolemia. A urine specific gravity of
1.020 or greater also suggests hypovolemia, and ketones of 2+ or greater
suggest starvation ketosis.
• Perform a rectal examination and obtain a sample of stool for occult blood
testing and for Wright's or Gram stain. If the rectal ampulla is empty, you can
still swab the mucosa, and may get an even better specimen for stool culture.
A spontaneous specimen is also good. If the patient has recently been on
antibiotics, test the stool for clostridim difficile.
• If there are any white cells in a 400x field, assume the problem is invasive or
inflammatory (Campylobacter, Salmonella, Shigella, Entameba, ulcerative
colitis, et cetera). Send a stool culture, prescribe ciprofloxacin 500mg bid x 3d,
and schedule follow up. Ask the patient to bring a fresh stool sample in a
specimen cup at follow up in case it needs to be examined for ova and
parasites.
• If there no white blood cells on microscopic examination of the stool, assume
the diarrhea is due to a virus or toxin. Afebrile patients with limited diarrhea
require no treatment eother than fluid and electrolyte replacement. These
patients will not benefit from antibiotics, and require follow up only if they
have continued diarrhea, abdominal pain, or fever.
• Both classes of diarrhea are best treated with absorbent bulk laxatives, such
as bran or ground psyllium seeds (Metamucil 1 tbsp in a glass of water up to
qid).
• To adsorb toxins and provide some binding effect, add Amphogel, Diasorb or
Kaopectate, 1 tbsp qid, or bismuth subsalicylate (Pepto- Bismol) 2 tbsp each
half-hour until symptoms subside, or to a total of eight doses (this does
contain salycilates, and bismuth will turn stools black).
• With infants and small children, oral rehydration therapy should be the main
treatment. Antimicrobial drugs shouls be given only for dysentery (bloody

2. diarrhea) and suspected cholera. Have the patients give an oral rehydration
mixture with the goal of replacing the fluid lost. For every one cup of diarrhea
lost, give a cup of the following recipe:
o 1/2 to 1 cup precooked baby rice cereal
o 2 cups water
o 1/4 teaspoon salt
Mix the rice cereal, water ans salt together until the mixture thickens but is
not too thick to drink. Be sure the ingredients are well mixed. Have the
parents give the mixture by spoon often and have them offer the child as
much as he will accept (every minute if he will accept it). Even if the child is
vomiting, the mixture can be offered in small amounts (1/2 - 1 tsp) every few
minutes. Banana or other non-sweetened mashed fruit can help provide
potassium. Alternatively, one can give commercial rehydration fluids sold in
drugstores like Rehydralate, Ricelyte or Pedialyte.
• During or after diarrhea, children should be given small meals frequently (six
or more times a day) and actively encouraged to eat. Parents should use well-
cooked staple starches that can be easily digested such as rice, corn, potatoes
or noodles in a soft mashed form. For infants, they should use a thick porridge
or semi-liquid pulp.
• Patients with severe dehydration that cannot be reversed orally may require
large amounts of intravenous fluids and occasionally must be admitted to the
hospital.
What not to do:
•
• Do not omit the rectal exam, which may disclose a fecal impaction or abscess.
• Do not stop or reduce breast feeding when a baby has diarrhea. Infants with
diarrhea should be breastfed as often and for as long as they want.
• Do not give give or recommend sugary drinks such as Gatorade, sweetened
commercial fruit drinks, cola drinks or apple juice, which may cause an
osmotic diarrhea and a net loss of fluid.
• Do not give additional aspirin-containing drugs to patients taking bismuth
subsalicylate (Pepto-Bismol)
Discussion
Most cases of mild to moderate diarrhea (defined as no more than five unformed
stools a day without fever, blood or significant cramps, pain, nausea or vomiting) can
be handled without an investigation of the etiology.
When you prescribe bran or psyllium, patients may remind you that they have
diarrhea, not constipation, but, because these agents absorb water in the gut lumen,
they can relieve both problems, and obviate the rebound constipation often produced
by the narcotic and binding agents also used to treat diarrhea.

3. The three commonest causes of diffuse colonic inflammation and thus fecal leukocyte
exudate are Shigella, Salmonella and Campylobacter. Fecal leucocytes can also be a
sign of ulcerative colitis and allergic colitis.
Most bacterial diarrheas do not require treatment with antibiotics, which can produce
a carrier state. The presumptive ciprofloxacin strategy described for the ED will suite
most patients, but may have to be modified in follow up based upon the patient's
course and stool culture results. Early empiric treatment of traveller's diarrhea with a
single 500mg dose of ciprofloxacin can reduce the duration and severity of the
illness.
Infants can become severely dehydrated in short order with viral diarrhea. Old
patients medicated for pain or psychosis can develop a fecal impaction which can
also present as diarrhea. Irritable bowel syndrome, food allergy, lactose intolerance
and parasite infestation can produce relapsing diarrhea, but the pattern may only
become apparent on follow up.