Differential diagnosis of diarrheal diseases

Differential diagnosis of diarrhea is based on anamnestic data and basic objective examination. If the patient does not report a recent stay in tropical or subtropical areas, we can consider one of the 4 groups of diseases (enterotoxicosis; acute infectious diarrhea; conditions mimicking acute infectious diarrhea; subacute, chronic, or recurrent diarrhea).

Enterotoxicosis
They are formed after the ingestion of foods containing bacterial toxins. The stool is watery, yellow, without mucus and blood. The predominant symptom is vomiting. They have a short incubation period, the initial course is very turbulent, but the disease quickly subsides. The treatment consists of intensive rapid rehydration.

The most common agents include Staphylococcus aureus, Bacillus cereus a Clostridium perfringens.

Acute infectious diarrhea in the strict sense
Their cause is the overgrowth of pathogenic microorganisms in the intestines. The main symptoms include fever and abdominal pain. A mixture of blood and mucus appears in the stool. If the disease is of bacterial origin, vomiting occurs rarely or not at all, but stool is more often mixed with mucus and blood. On the contrary, diarrhea of viral origin is accompanied by vomiting, the stool is watery. The disease usually lasts for several days.

The treatment is rehydration again. Based on the culture examination of the stool the etiological agent is determined, which further determines the need for isolation or the use of antibiotics.


 * Bacterial etiology: Salmonella enterica, Campylobacter jejuni, Shigella species, Yersinia enterocolitica, Enterotoxické E. coli, Clostridium difficile.
 * Viral etiology: rotaviruses, noroviruses, enteroadenoviruses.

Inflammatory bowel diseases of unknown etiology
See Crohn's disease for more information.

See Ulcerative Colitis for more information.

The main representatives are ulcerative colitis and Crohn's disease. These diseases are accompanied by fever, diarrhea with mucus, and blood. In the laboratory, we find an increase in inflammatory parameters. The data of repeated attacks in the past is important.

Severe disease with a cause outside the digestive tract



 * Sudden abdominal event – the main symptom is abdominal pain, subileous to ileotic condition.
 * Ectopic pregnancy is a severe condition accompanied by pallor, weakness, and hypotension. There is a history of menstrual failure.
 * Severe sepsis – an example is a diarrhea at the onset of meningococcal sepsis.
 * Toxic shock syndrome is accompanied by diarrhea, fever, rash, and hypotension.
 * Legionellosis is a disease with major symptoms such as diarrhea, pneumonia, or encephalopathy.

Subacute, chronic, or recurrent diarrhea
The longer the disease lasts, the higher the probability of non-infectious etiology. Of inflammatory diseases (i.e. with an increase in inflammatory markers) can be Crohn's disease or ulcerative colitis. The reasons are also other serious, noninflammatory disorders, e.g. irritable bowel syndrome, rectal cancer, colonic polyps, conditions after bowel resection syndrome blind loop, chronic pancreatitis, intolerance to certain food components (lactose), malabsorption syndromes or endocrine disorders (hyperthyroidism, diabetes mellitus).

Infectious diseases are also the cause, especially opportunistic infections - clostridial colitis, parasitic infections, HIV/AIDS.

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