Shigellosis

Synonyms

Shiga bacillus dysentery; Shigella dysentery

Definition

Before defining shigellosis, it is necessary to clarify the meaning of a few terms commonly employed in the gastroenterology clinic. Diarrhea means the passage of three or more unformed stools per day. It can be a symptom of colitis, which is a disease characterized by the presence of a histological lesion: colonic inflammation. The inflammatory process may be limited to the mucosa or extend to the deeper layers of the bowel wall. The diagnosis of colitis can be established when, in a patient with diarrhea, one or more of the following features are present: (1) passage of multiple small-volume stools containing blood and mucus (this symptom is called “dysentery”), (2) positive markers for colonic inflammation in the stools (leukocytes adherent to the mucus on microscopic examination, positive fecal lactoferrin or calprotectin test), and (3) colonoscopy showing mucosal inflammation. Colitis is classified as acute when it...