Laxatives are the most common medicinal treatment for constipation and are usually available over-the-counter. Common forms of OTC laxatives include fiber supplements, stimulants (drugs that cause your intestines to contract), osmotic laxatives (such as Milk of Magnesia), and stool softeners (drugs that draw water from the intestines to loosen and soften the stool).
In addition to these drugs, prescription medications such as lubiprostone, linaclotide, and plecanatide help treat constipation by increasing fluid levels in the intestines. This helps moisturize and loosen the stool, making it easier to pass.
Talk to your doctor before taking any laxatives or prescription medication. If you are taking prescription medication to treat chronic constipation, talk to your doctor before discontinuing the use of the drug.