Enterotoxin and exotoxin are two classes of toxin that are produced by bacteria.

An exotoxin is a toxin that is produced by a bacterium and then released from the cell into the surrounding environment. The damage caused by an exotoxin can only occur upon release. As a general rule, enterotoxins tend to be produced by Gram-positive bacteria rather than by Gram-negative bacteria. There are exceptions, such as the potent enterotoxin produced by Vibrio cholerae. In contrast to Gram-positive bacteria, many Gram-negative species posses a molecule called lipopolysaccharide. A portion of the lipopolysaccharide, called the lipid A, is a cell-associated toxin, or an endotoxin.

An enterotoxin is a type of exotoxin that acts on the intestinal wall. Another type of exotoxin is a neurotoxin. This type of toxin disrupts nerve cells.

Many kinds of bacterial enterotoxins and exotoxins exist. For example, an exotoxin produced by...