Question

Regarding the assertion and reason; choose the correct option.

Assertion (A): In case of acute constipation, purgatives containing magnesium salts are usually used to alleviate it

Reason (R): The osmotic effect of Mg²⁺ in the intestinal lumen prevents water from being reabsorbed from the intestine. Mg²⁺ increases the solute concentration in the intestinal lumen because Mg²⁺ is absorbed very slowly

• A. Assertion [A] is True and Reason [R] is False
• B. Reason [R] is True and Assertion [A] is False
• C. Assertion [A] is True and Reason [R] is True and is a correct explanation to [A].
• D. Assertion [A] is True and Reason [R] is True but is not a correct explanation to [A].

Answer 1

The correct option is C

Assertion [A] is True and Reason [R] is True and is a correct explanation to [A].

The Mg²⁺ ions in the purgatives increase the solute concentration in the intestinal lumen because Mg²⁺ ions are absorbed very slowly. The osmotic effect of Mg²⁺ prevents the absorption from the intestine. Additionally, Mg²⁺ also draws water from the blood into the intestinal lumen by osmosis, thus relieving the person from the acute constipation condition.