Question

Maximum water reabsorption in the gastrointestinal tract occurs in?

• A. Stomach
• B. Jejunum
• C. Ileum
• D. Colon

Hint:

Think of the proximal small bowel with its leaky, high-surface villous epithelium.

Answer 1

The Correct Option is B

Step 1: Water in the gut is never digested. It is simply absorbed passively along the osmotic gradient created when sodium, glucose and amino acids are pumped out of the lumen into the blood.

Step 2: The daily fluid load reaching the intestine is close to 9 L (drink plus the combined secretions of salivary glands, stomach, pancreas, liver and gut wall). Almost all of this must be recovered to avoid massive fluid loss.

Step 3: The proximal small bowel, particularly the jejunum, has the most leaky tight junctions and the largest surface area from its villi and microvilli. Because it follows solute absorption fastest, it reclaims the greatest share of luminal water. The ileum and colon handle progressively smaller residual amounts.

Step 4: Therefore, comparing all four sites, the jejunum is where the highest quantity of water is reabsorbed.

\[\boxed{\text{Jejunum}}\]