Chapter 40. The Intestines: II. Infections; Inflammatory Bowel Diseases

Classification

Intestinal infections can be divided into 3 broad groups (Table 40-1):

1. Enterotoxin-mediated, where the disease is caused by a bacterial exotoxin; the organism does not invade the tissues and in some cases does not even enter the body (staphylococcal toxin, botulism), as the exotoxin is preformed in food.

2. Invasive infections, where the organism invades the intestinal mucosa.

3. Noninvasive infections, where the organism exists in the intestinal lumen and does not invade the tissues.

Most intestinal infections are transmitted by fecal contamination of food or drinking water. They are common in parts of the world where public health sanitary measures such as disposal of feces and purification of water supplies are not adequate.

Clinically, infections that involve the small intestine result in profuse watery diarrhea, while those that involve the colon produce dysentery (frequent small-volume diarrhea with blood and mucus). Fever is present in most invasive infections but is often absent in enterotoxin-mediated diseases.

Diagnosis

(Table 40-2)