Metamucil is the name brand of a type of bulk-forming fiber laxative. It is available in several forms and flavors, and works to treat bowel irregularity and constipation. It does so by absorbing some of the liquid that is present in the intestines, which then results in swollen stools that are easier to pass. This type of fiber laxative is comprised of psyllium husks.

Patients who have diabetes, abnormal blood sugar fluctuation, high blood pressure, or PKU may wish to discuss the use of this medication with their physician, as there may be sugar, sodium, or artificial sweeteners in Metamucil. The typical consumer may not notice any side effects, however, bloating and a change in bowel movements are not uncommon. Abdominal fullness has also been reported, and tends to be more frequently noticed during the first days of use.

As with the vast majority of medications, Metamucil could potentially cause a variety of allergic reactions. If a person were to experience any type of reaction that might be an allergic reaction, he or she will probably be advised to contact the prescribing physician, a pharmacist, or Emergency Medical Services as appropriate.

The possible Metamucil side effects include nausea or vomiting, tightness in the chest which may also appear with trouble breathing, gas and a rash or hives. Although less common, rectal bleeding, choking or trouble swallowing, and constipation that lasts more than a week has also been reported. Potentially life threatening allergic reactions may occur, and many people consider these to be the same thing as side effects. Esophageal impaction has been reported a few times, almost always after use of an overnight product, as have duodenal bezoars. The medical records that pertain to Metamucil also have documented one occurrence of Eosinophilia, which is a type of blood disorder.

Metamucil has available to the public, over the counter, and without a prescription for many years. It is generally regarded as a safe medication, and is a common topic of discussion at medical appointments. Some experimentation may be necessary to determine the effective dose. The lowest effective dose, not to exceed the manufacturer's directions should be consumed.