Final answer:
The main reason for diarrhea with hypertonic tube feedings is the high osmolarity drawing water into the gastrointestinal tract due to too much solute in the feeding solution.
Step-by-step explanation:
The main reason a client receiving hypertonic tube feedings may experience diarrhea is due to the high osmolarity of the feeding solution. When a solution is hypertonic, it means that it contains too much solute compared to the fluids within the body's cells.
This high concentration of solutes, such as sugars, electrolytes, or proteins, can draw water into the gastrointestinal tract from the surrounding tissues by osmosis, increasing fluid content and leading to diarrhea.
Moreover, similar mechanisms of fluid and electrolyte secretion can be seen in certain infections, where bacterial toxins (e.g., from V. cholerae) lead to the activation of adenylate cyclase in intestinal cells.
This results in increased levels of cyclic adenosine monophosphate (CAMP), which activates chloride channels and triggers a release of fluids and electrolytes from cells into the intestinal lumen, causing watery diarrhea.