Required Knowledge base to manage patients with Acute Diarrhea
Dr A.J. Chandrasekhar

Normal stool 

• Normal bowel frequency ranges from three times a week three times a day

• Weight 200 g/d

Definition for diarrhea

The definition of diarrhea is somewhat controversial.  It depends on the patient’s as well as the physician’s perspective.  

• Patients usually consider diarrhea as being an increase in the daily frequency, liquidity, or volume of the stool.  

• Also an urgency to defecate. 

• Scientifically, diarrhea exists if more that 300 gms stool is passed daily on the Western diet. 

• Clinically, it may be defined as an increased number of stools/day. 

• Relative to what the patient’s “usual” habit has been. 

It is important to take a good history and ask appropriate questions regarding stooling.  Don’t just accept the patient’s statement of diarrhea. 

Pseudodiarrhea or hyper defecation

Increase in frequency without an increase in weight of the stool.

• Irritable bowel syndrome

• Proctitis

• Hyperthyroidism

Fecal incontinence

• Involuntary release of rectal contents

Classification of Diarrhea

• Diarrhea lasting two weeks or less is considered to be Acute Diarrhea

• Diarrhea lasting longer than two weeks or is intermittent over months or years  is considered Chronic Diarrhea.

• Acute Diarrhea

  • lasts two weeks or less

  • self-limited

  • requiring no diagnostic work-up 

  • symptomatic treatment only (fluids) 

  • Acute diarrhea should be investigated only if there is

    • evidence of tissue invasion such as blood or pus in the stool 

    • fever 

    • leukocytosis 

    • severity that produces significant fluid and electrolyte loss  

• Chronic diarrhea 

  • lasts longer than two weeks 

  • or is intermittent over months or years 

  • This form requires a diagnostic work-up and a treatment strategy

Questions to ask a patient with acute diarrhea        

• Compare the patient’s usual or normal frequency and pattern with that of the current pattern or frequency.  

• Ask about the characteristics

  • Watery, bulky, color, presence of blood or pus

• Change in odor 

• Change in timing   

  • Frequency, duration

  • Continuous, intermittent

  • Time of day or night

  • Diarrhea alternating with constipation : Irritable bowel syndrome, Cancer colon

• Precipitating events such as food or drug

• Causes of relief

• Ask about associated symptoms 

  • Fever, nausea, vomiting, abdominal pain, anorexia: Inflammatory diarrhea

  • Symptoms of autonomic dysfunction: Diabetic diarrhea

  • Flatulence and bloating : Intestinal mucosal disease

  • Arthritis, skin lesions, ocular symptoms: Idiopathic inflammatory bowel disease

• Ask about predisposing  factors such as travel, diet, drug history, family history, other medical surgical problems.

Physical findings  you should look for in the evaluation of a patient with Acute diarrhea

Investigational options in the workup of patients with acute diarrhea

Stool

• Blood and leukocytes in stool : Inflammatory diarrhea. Inflammatory colonic disease. 

• Stool for ova and parasites

• Stool for C/S

• C. dificile toxin. 

Bowel changes

• Colonoscopy indicated if stool is negative for pathogens. Colonic mucosa may have to be looked at endoscopically and biopsied if inflammatory bowel disease is suspected. 

Common etiologies for acute diarrhea

Infectious

• Viruses

• Bacteria

  • Toxins S aureus, C difficile, toxigenic E.coli

  • Invasion Shiegella, Salmonella

• Parasites Giardia, Cryptosporidium

Non-infectious.

• Drugs 

  • laxatives

  • antacids

  • alcohol

  • antibiotics 

  • chemotherapy

  • a host of other pharmaceuticals used in everyday practice

• Food toxins / Preformed toxins / Starts within several hours following ingestion / Rarely fever

  • Mushrooms

  • Seafood

• Metabolic causes (hyperthyroidism)

• Motor disorders such as irritable bowel syndrome

• Redemption of enteral feeding following prolonged fast

• Fecal impaction

Onset of chronic diarrhea

People at risk for acute diarrhea

• Developing nations

• Who ingest shell fish

• Male homosexuals

• AIDS

• IV drug users

• Residential homes/ nursing homes

• Day care centers

Acute diarrhea should be investigated only if there is evidence of tissue invasion such as blood or pus in the stool , fever,  leukocytosis severity that produces significant fluid and electrolyte loss  Diagnostic workup might include

• Stool for ova and parasites

• Stool for blood, leukocytes

• C difficile toxin

• Stool cultures

• Proctosigmoidoscopy