What is the reason magnesium salts help relieve constipation?

Magnesium salts are known for their osmotic laxative effect, which is primarily due to their ability to attract and hold water in the intestines. When magnesium salts are ingested, they increase the osmolarity of the intestinal contents, leading to more water being drawn into the intestines from the bloodstream. This influx of water helps to soften the stool, making it easier to pass and relieving constipation.

The mechanism involves the interaction of magnesium with the intestinal walls, promoting a favorable environment for bowel movements. As more water accumulates in the intestines, it stimulates peristalsis (the involuntary contraction of intestinal muscles), further aiding the movement of fecal matter through the digestive tract.

Other options do not directly relate to how magnesium salts relieve constipation. While glucose absorption and muscle contractions are important physiological processes, they do not specifically address the constipation relief effect of magnesium salts. Additionally, creating an isotonic environment is not the primary function of magnesium; instead, it is the osmotic effect of magnesium that plays a crucial role in alleviating constipation.