Laxative Option Rx: What You Need To Know

Rx laxatives are prescription laxatives that are often used to treat chronic constipation. They are typically used when over-the-counter (OTC) laxatives have failed to provide relief. Rx laxatives work in different ways, including softening stools, increasing the frequency of large colon contractions, and drawing water into the bowel to aid stool passage. Rx laxatives are generally safer for long-term use under medical supervision, while OTC laxatives are meant for short-term relief.

Bulk-forming laxatives

Common bulk-forming laxatives include psyllium (Metamucil), polycarbophil (FiberCon), methylcellulose (Citrucel), Fybogel (ispaghula husk), inulin (Metamucil Simply Clear), wheat dextrin (Benefibre), and calcium polycarbophil (Colace).

When taking bulk-forming laxatives, it is important to follow the instructions provided and not exceed the recommended dosage. They should also be taken with at least 8 ounces of water or fruit juice to prevent bowel obstruction. It is also important to stay well-hydrated throughout the day, as these laxatives can cause dehydration.

Osmotics

Osmotic laxatives are medications used to treat or prevent constipation. They are available over the counter and by prescription. Osmotic laxatives work by drawing water into the bowel to help soften stools so that they pass more easily. This type of laxative is particularly useful for treating chronic constipation.

Osmotic laxatives increase the amount of fluid in the intestines, which softens stools and makes them easier to pass. The term "osmotic" refers to the movement of fluid through a membrane so that the concentration is equal on both sides. In people with constipation, the concentration of water in the wall of the colon and the inside of the colon (called the lumen) will be balanced but too low to compensate for hard, dry stools. Osmotic laxatives alter the balance with substances such as salts, sugars, and other organic compounds that encourage the movement of water into the lumen.

Some common osmotic laxatives include:

• Polyethylene glycol (PEG): An organic compound derived from petroleum that can be safely ingested to manage constipation. Available over the counter, PEG-containing laxatives include Miralax and GlycoLax.
• Lactulose: A type of sugar that is not absorbed by the intestine. Instead, it sits and ferments in the intestines, producing fatty acids that draw water into the lumen. Available by prescription, lactulose-containing laxatives include Cephulac, Duphalac, and Kristalose.
• Sorbitol: Another non-absorbable sugar with an action similar to lactulose. Over-the-counter (OTC) and prescription versions are available, including Arlex and GeriCare.
• Magnesium citrate: Magnesium in salt form combined with citric acid. The salts help draw water into the lumen. OTC versions include Citrate of Magnesia, Citroma, and LiquiPrep.
• Magnesium hydroxide: A milder form of magnesium sold under the brand name Milk of Magnesia. Available over the counter, Milk of Magnesia is also used as an antacid.

Common side effects of osmotic laxatives include nausea, bloating, cramping, flatulence, and diarrhea. Overuse of osmotic laxatives can lead to dehydration and the loss of electrolytes like sodium, calcium, and potassium.

Stool softeners

It is recommended to take stool softeners at bedtime, following the directions on the packaging or as prescribed by a healthcare provider. They should only be taken when needed and for a short duration, typically not exceeding one week unless under medical supervision. Side effects may include stomach pain, nausea, diarrhoea, throat irritation (from oral forms), and, in rare cases, a serious allergic reaction.

Lubricants

Lubricant laxatives are used to treat constipation by coating the stool and the inside of the bowel with moisture, which helps keep the stool from drying out. This allows for smoother passage along the intestines and colon. Lubricant laxatives include mineral oil, which can be administered as an enema or taken orally as a liquid.

Lubricant laxatives are available over the counter and do not require a prescription. They may take effect within 6 to 8 hours of being taken. However, they should not be used long-term as they could lead to dependence. Long-term use could also result in vitamin deficiencies, particularly vitamins A, D, E, and K. It is important to consult a healthcare professional before taking any laxatives, especially if you are pregnant or breastfeeding.

Stimulants

Stimulant laxatives are used to treat constipation. They are usually recommended for people with severe constipation who have not found relief with other treatments. They stimulate the nerves that control the muscles in the colon, forcing the colon into motion and helping to pass stool. They are one of the faster-acting types of laxatives, taking 6 to 12 hours to work.

The active ingredient in stimulant laxatives is typically either senna (also known as sennosides) or bisacodyl. Senna is a natural stimulant laxative derived from the leaves and pods of the senna plant. It has a long history of use as a laxative, dating back to ancient times. It works by increasing fluid secretion and muscle contractions in the intestines, making it easier to pass stool. Bisacodyl, on the other hand, is a synthetic stimulant laxative that is available in various forms, including liquids, powders, chewables, tablets, and suppositories. Some common brand names of stimulant laxatives that use bisacodyl include Correctol, Dulcolax, and Carter's Little Pills.

It is important to note that stimulant laxatives are meant for short-term use only and should not be used for more than a week unless specifically advised by a doctor. Overusing stimulant laxatives can lead to serious side effects, including addiction, and can be harmful to the bowels if used for an extended period. They should not be given to children under six unless instructed by a pediatrician. Before using a stimulant laxative, it is essential to consult a doctor, especially if you have any current health conditions, are pregnant, or are breastfeeding.

Some possible side effects of stimulant laxatives include:

• Diarrhea
• Abdominal pain
• Cramping
• Nausea
• Vomiting
• Allergic reactions
• Urine discolouration (when using senna)

If you experience any of these side effects, or if you have no bowel movement after taking a stimulant laxative, it is important to consult a healthcare provider.

Frequently asked questions