Which statement best describes the most likely sequence in severe diarrhea?

Which statement best describes the most likely sequence in severe diarrhea?

• A. Water moves from intestines into the blood to dilute plasma.
• B. The body experiences tissue-to-blood shift without any water loss.
• C. The primary immediate event is water loss from the body via the gut, followed by a tissue-to-blood fluid shift.
• D. Blood osmolality decreases as water is lost.

Answer: (C)

In severe diarrhea, the first thing that happens is a loss of fluid directly from the gut into the stool. This reduces the body's total water and extracellular fluid volume. As those losses occur, plasma osmolality can rise because water is being removed without an immediate, proportional loss of solutes. To help stabilize the situation, water then shifts from the intracellular (tissue) compartment into the extracellular (blood/plasma) compartment to rebalance osmolarity and support circulating volume. That sequence—water loss via the gut first, followed by a tissue-to-blood fluid shift—best describes what happens in this scenario. The other statements don’t fit because GI fluid loss isn’t a movement of water from the gut directly into the blood to dilute plasma, there is indeed water loss, and blood osmolality tends to rise, not decrease, with GI fluid losses.

In severe diarrhea, the first thing that happens is a loss of fluid directly from the gut into the stool. This reduces the body's total water and extracellular fluid volume. As those losses occur, plasma osmolality can rise because water is being removed without an immediate, proportional loss of solutes. To help stabilize the situation, water then shifts from the intracellular (tissue) compartment into the extracellular (blood/plasma) compartment to rebalance osmolarity and support circulating volume. That sequence—water loss via the gut first, followed by a tissue-to-blood fluid shift—best describes what happens in this scenario.

The other statements don’t fit because GI fluid loss isn’t a movement of water from the gut directly into the blood to dilute plasma, there is indeed water loss, and blood osmolality tends to rise, not decrease, with GI fluid losses.