Key takeaways
Calcium polycarbophil (FiberCon) and magnesium citrate (Citroma) are both over-the-counter medications used to treat occasional constipation, but they work differently and have distinct characteristics. Calcium polycarbophil is a bulk-forming laxative that keeps water in the stool, making it easier to pass, and typically takes 12 to 72 hours to produce a bowel movement. In contrast, magnesium citrate is a saline laxative that helps your intestines hold onto water, usually working within 30 minutes to 6 hours. FiberCon is a synthetic fiber supplement and is less likely to cause gas and bloating compared to natural fiber supplements like Metamucil. On the other hand, magnesium citrate can cause nausea and vomiting and is not recommended for people with kidney problems or electrolyte imbalances. While both medications should be taken with plenty of water, magnesium citrate comes in liquid form and can be flavored, whereas FiberCon is available in tablet form.
