Thursday, May 27, 2021

Acute Diarrhea Case File

Posted By: Medical Group - 5/27/2021 Post Author : Medical Group Post Date : Thursday, May 27, 2021 Post Time : 5/27/2021
Acute Diarrhea Case File
Eugene C. Toy, MD, Barry C. Simon, MD, Terrence H. Liu, MD, MHP, Katrin Y. Takenaka, MD, Adam J. Rosh, MD, MS

Case 21
A 19-year-old woman is brought into the emergency department (ED) complaining of abdominal pain and diarrhea of 3-day duration. She has also been nauseous and has not been able to drink much liquid. Five days ago she returned from a camping trip in New Mexico, but did not drink from natural streams. She denies fever, but states that she has had some chills. Her stools have been watery, brown, and profuse. The patient denies health problems. On examination, the patient is thin and pale. Her mucous membranes are dry. Her temperature is 37.2°C (99°F), heart rate 110 beats per minute, and blood pressure 90/60 mm Hg. The skin has no lesions. Her heart and lung examinations are unremarkable except tachycardia. The abdominal examination reveals hyperactive bowel sounds and no masses. There is diffuse mild tenderness but no guarding or rebound. Rectal examination demonstrates no tenderness or masses, and is Hemoccult negative. The complete blood count reveals a leukocyte count of 16,000 cells/mm3. The pregnancy test is negative.

 What is the most likely diagnosis?
 What is the next diagnostic step?
 What is the next step in therapy?

Acute Diarrhea

Summary: A 19-year-old healthy woman presents to the ED with a 3-day history of abdominal pain, nausea, and non-bloody, watery, profuse diarrhea. Five days ago, she was on a camping trip in New Mexico but did not drink from natural streams. Her mucous membranes are dry. Her temperature is 37.2°C (99°F), heart rate 110 beats per minute, and blood pressure 90/60 mm Hg. The abdominal examination reveals hyperactive bowel sounds, no masses, and diffuse mild tenderness without peritoneal signs. Rectal examination is occult blood negative. The leukocyte count is 16,000 cells/μL. The pregnancy test is negative.
  • Most likely diagnosis: Acute volume depletion and possible electrolyte abnormalities
  • Next diagnostic step: Stool for fecal leukocytes
  • Next step in therapy: Intravenous fluid hydration

  1. Know a diagnostic approach to acute diarrhea including the role of fecal leukocytes and assessment for occult blood in the stools.
  2. Understand that volume replacement and correction of electrolyte abnormalities are the first priorities in treatment of diarrhea.
  3. Be familiar with a rational workup for acute diarrhea, and know the common etiologies of diarrhea, including Escherichia coli, Shigella, Salmonella, Giardia, and amebiasis.
This 19-year-old woman developed severe diarrhea, and nausea. Her most immediate problem is volume depletion as evidenced by her dry mucous membranes, tachycardia, and hypotension. The first priority should be for acute replacement of intravascular volume, usually with intravenous normal saline. The electrolytes should be assessed, and abnormalities, such as hypokalemia, should be corrected. After volume repletion, the next priority is to determine the etiology of the diarrhea. Up to 90% of acute diarrhea is infectious in etiology. This patient does not have a history consistent with inflammatory bowel disease or prior abdominal surgeries. She had been camping in New Mexico recently, which predisposes her to several pathogens: E coli, Campylobacter, Shigella, Salmonella, and Giardia. She does not have grossly bloody stools which would usually mandate an evaluation, and suggests invasive bacterial infections such as hemorrhagic or enteroinvasive E coli species, Yersinia species, Shigella, and Entamoeba histolytica. Additionally, the stool for occult blood is negative. Fetal leukocyte is an inexpensive and good test to differentiate between the various types of infectious diarrhea. If the fecal leukocytes are present in the stool, the ED physician may have a higher suspicion for Salmonella, Shigella, Campylobacter, Clostridium difficile, Yersinia, enterohemorrhagic and enteroinvasive E coli, and E histolytica. Stool cultures are helpful. In general, ova and parasite evaluation is unhelpful unless the history strongly points toward a parasitic source, or the diarrhea is prolonged. Most diarrheas are self-limited, and do not need evaluation. Table 21–1 summarizes the danger signs. Because of the severity of this patient’s symptoms, empiric antibiotic therapy such as with ciprofloxacin might be indicated.

etiologies of diarrhea

Data from Ahlquist DA, Camilleri M. Diarrhea and constipation. In: Braunwald E, Faucis AS, Kaspar DL, et al, eds.
Harrison’s Principles of Internal Medicine. 15th ed. New York, NY: McGraw Hill; 2001.

Approach To:
Acute Diarrhea

ACUTE DIARRHEA: Present for less than 2-week duration.

CHRONIC DIARRHEA: Diarrhea present for greater than 4-week duration.

DIARRHEA: Passage of abnormally liquid or poorly formed stool in increased frequency.

SUBACUTE (PERSISTENT) DIARRHEA: Present for 2- to 4-week duration.


Approximately 90% cases of acute diarrhea are caused by infectious etiologies, and the remainder is caused by medications, ischemia, or toxins. Infectious etiologies often depend on the patient population. For instance, travelers to Mexico or Asia will frequently contract enterotoxigenic E coli as a causative agent. Those traveling to Russia and campers and backpackers will often be affected by Giardia. Campylobacter, Shigella, and Salmonella are also common causative agents.

Consumption of foods is also frequently a culprit. Salmonella or Shigella can be found in undercooked chicken, enterohemorrhagic E coli in undercooked hamburger, and Staphylococcus aureus or Salmonella in mayonnaise. Raw seafood may harbor Vibrio, Salmonella, or hepatitis A, B, or C. Sometimes the timing of the diarrhea following food ingestion is helpful.

For example, illness within 6 hours of eating a salad (mayonnaise) suggests S aureus, 8-12 hours post-ingestion suggests Clostridium perfringens, and 12 to 14 hours post-ingestion suggests E coli (see Table 21–1).

Day-care settings are particularly common locales for Shigella, Giardia, and rotavirus transmission. Patients in nursing homes and who were recently in the hospital may develop C difficile colitis from antibiotic use. In addition, immunecompromised patients with prior history of C difficile infections may remain colonized and recurrent clinical infections despite appropriate treatment.

Clinical Presentation
Most patients with acute diarrhea have self-limited processes, and do not require much workup. Exceptions to this rule include profuse diarrhea, dehydration, fever exceeding 38.5°C (101.3°F), grossly bloody diarrhea, an elderly patient, severe abdominal pain, duration exceeding 48 hours without improvement, and an immunocompromised patient. Mortalities related to diarrheal illnesses are generally due to the inadequate recognition and treatment of dehydration, electrolyte disturbances, and acidosis.

The history should be meticulous about trying to identify prior history of GI complaints, exposure history including medications, foods, travel history, and contacts with individuals with similar symptoms. A history of recent viral illness may provide clue to the etiology. Occupational history may help identify infectious sources.

The clinician should determine what the patient can tolerate orally; in other words, if the patient is both vomiting and having profuse diarrhea, severe dehydration is likely. The amount and character of the stools may be helpful to determine etiology, as well as direct therapy.

The physical examination should focus on the vital signs, clinical impression of the patient’s hydration status, indicators of sepsis, mental status, and abdominal examination. The patient’s hydration status is determined by observing whether the mucous membranes are moist or dry, skin has good turgor or is tenting, jugular venous distention, and capillary refill. The principal laboratory test is the stool for microscopic and microbiological examination. Stool culture results generally require several days to become finalized and are not useful in the ED setting; however, these results may be helpful for follow-up evaluations and for patients who do not improve with initial management. Ova and parasite evaluation is generally unhelpful except in selected circumstances of very high suspicion. Stool for C difficile toxin may yield the etiology in patients who develop symptoms after antibiotic use, and in most instances, the enzyme immunoassay results may be available in as little as two hours. Although pseudomembranous colitis was classically associated with clindamycin usage, fluoroquinolones are reported recently as the most common antibiotics contributing to the condition. C difficile infections are also being increasingly reported in patients with inflammatory bowel disease (IBD), where the symptoms may be difficult to differentiate from an exacerbation of IBD. A complete blood count, electrolytes, and renal function tests are sometimes indicated.

Traveler’s diarrhea most often presents as watery diarrhea occurring a few days after traveling to Mexico, South America, Africa, or South Asia. This type of diarrhea is most often caused by enterotoxigenic E coli, which can produce diarrhea from the generation of toxin leading to cholera-like symptoms; infections by enteroinvasive strains of E coli causing a shigella-like illness that is manifested by bloody mucous-producing diarrhea; and chronic infections related to E coli overgrowth. Fluids and electrolyte replacements are the mainstay of treatment for traveler’s diarrhea. A number of agents are helpful in reducing stool frequency, and these agents include bismuth subsalicylate and loperamide.

Antibiotic therapy may be indicated when symptoms do not resolve with supportive care and stool-reducing agents. For travelers returning from the non-coastal regions of Mexico, double-strength trimethoprin-sulfamethoxazole twice a day is recommended. For other patients, ciprofloxacin (750 mg), levofloxacin (500 mg), norfloxacin (800 mg), or azithromycin (1000 mg) are recommended. For immune compromised patients and elderly patients with comorbidities, prophylaxis with trimethoprim-sulfamethoxazole or a fluoroquinolone can be prescribed.

If the etiology is still unclear and the patient is not improving while off oral intake, hospital admission and consultation with a gastroenterologist may be indicated. Radiological studies or endoscopy may be needed to determine the cause. Diseases such as inflammatory bowel disease or ischemic bowel disease must be considered.

Fluid and electrolyte replacement are fundamental to the treatment of acute diarrhea. For mildly dehydrated individuals who can tolerate oral fluids, sports drinks such as Gatorade orally are often all that is needed. In developing countries, the oral rehydration solution (ORS) introduced by the World Health Organization (WHO) has been shown to be well tolerated by patients and well received by care givers. For those with more serious volume deficits, or elderly patients or infants, hospitalization and intravenous hydration may be necessary. Bismuth subsalicylate may be used to alleviate the gastrointestinal symptoms, but should not be used in an immune-compromised individual because of the risk of bismuth encephalopathy. Many physicians choose to treat patients with moderately ill or severely ill appearance empirically with ciprofloxacin 500 mg twice daily for 5 days. Antimicrobial treatment may not alter the course of the disease.

Traveler’s Prophylaxis
The best method in preventing traveler’s diarrhea, which is principally caused by enterotoxigenic E coli, is avoidance of food and water in areas of high risk. Travelers should be advised to drink only bottled water, and avoid eating foods from street vendors or unhygienic locations. “Boil it, cook it, peel it, or forget it” remains a sound advice for individuals traveling to Latin America, the Caribbean, Africa, and South Asia. The CDC endorses bismuth subsalicylate, two 262-mg tablets chewed well four times a day (with meals and at bedtime), but does not advocate the use of antimicrobial agents because a false sense of security or antibiotic resistance may result. Nevertheless, many practitioners prescribe ciprofloxacin 500 mg once a day. Medical prophylaxis (either bismuth subsalicylate or antibiotic) should not be used for longer than 3 weeks.


Match the following etiologies (A to F) to the clinical situations in Questions 21.1
to 21.4:
        A. E coli
        B. Giardia
        C. Rotavirus
        D. S aureus
        E. Vibrio
        F. Cryptosporidium

21.1 During the winter, a 24-year-old woman who works at a day care develops profuse watery diarrhea.

21.2 A 22-year-old college student takes a trip during spring break to Cozumel and develops diarrhea.

21.3 Several workers develop watery diarrhea and significant emesis within 4 hours after eating food at a potluck dinner.

21.4 A 45-year-old man eats raw oysters and 2 days later develops abdominal cramping, fever to 38.3°C (101°F), and watery diarrhea.


21.1 C. Rotavirus usually causes a watery diarrhea, and is especially common in the winter.

21.2 A. E coli is the most common etiology for diarrhea in travelers visiting Mexico.

21.3 D. S aureus usually causes prominent vomiting and diarrhea within a few hours of food ingestion as a consequence of the toxin produced.

21.4 E. Raw seafood may harbor Vibrio spec; thus, the history of eating raw oysters makes Vibrio-related infection likely.


 The vast majority of acute diarrhea is caused by an infectious etiology.

 Most acute diarrheas are self-limited.

 One should be cautious when assessing acute diarrhea in immunosuppressed, patients, very young, or elderly patients.

 Significant dehydration, grossly bloody diarrhea, high fever, and nonresponse after 48 hours are warning signs of possible complicated diarrhea.

 In general, acute uncomplicated diarrhea can be treated with oral electrolyte-fluid solution with or without empiric ciprofloxacin.


Faris B, Blackmore A, Haboubi N. Review of medical and surgical management of Clostridium difficile infection. Tech Coloproctol. 2010:DOI 10.1007/s10151-010-0574-3. 

Hill Dr, Beeching NJ. Travelers’ diarrhea. Curr Opin Infect Dis. 2010;23:481-487. 

House HR, Ehlers JP. Travel-related infections. Emerg Med Clin N Am. 2008;26:499-516. 

Pigott DC. Foodborne illness. Emerg Med Clin N Am. 2008;26:475-497.


Post a Comment

Note: Only a member of this blog may post a comment.