Final answer:
Diseases such as Zollinger-Ellison, carcinoid syndrome, villous adenomas, and mastocytosis cause secretory diarrhea, characterized by increased secretion of fluids and electrolytes into the intestinal lumen. The correct option is b) Secretory
Step-by-step explanation:
Diseases such as Zollinger-Ellison, carcinoid syndrome, villous adenomas, and mastocytosis cause secretory diarrhea. These conditions are associated with an overproduction of certain hormones or other substances that lead to an increase in the secretion of fluids and electrolytes into the intestinal lumen, resulting in watery diarrhea. Specifically, hormones such as gastrin, which can be overproduced in these conditions, stimulate the gut to release more digestive secretions and cause the cells to pump out more chloride ions, which in turn draws water into the gut, leading to diarrhea.
Activation of adenylate cyclase in intestinal cells can lead to increased levels of cyclic adenosine monophosphate (CAMP) and subsequent secretion of fluids and electrolytes out of the cell. This mechanism of fluid secretion is similar to how Vibrio cholerae, the bacterium that causes cholera, results in profuse diarrheal illness. However, unlike osmotic diarrhea which occurs due to the inability to absorb certain substances leading to water retention in the gut, or inflammatory diarrhea which is a result of damage to the intestinal lining, secretory diarrhea is specifically a result of increased secretion into the gut lumen. The correct option is b) Secretory