Five ingredients.
Nothing hidden.

Stir psyllium into water and it turns to gel in minutes. That gel, called mucilage, is the whole trick: it holds water in the gut and bulks out stool, so it's softer and easier to pass.

1. CenturiesUsed across India and its neighbours as a bulk-forming remedy for sluggish bowels.
2. 1934G. D. Searle launches Metamucil in the US, named after mucilage, with psyllium husk as its active ingredient.
3. TodayIndia grows about 80% of the world's psyllium, mostly in Rajasthan and Gujarat.

Sources: Psyllium, Wikipedia · Science History Institute · Metamucil, Wikipedia · Business Today

Cut an Aloe ferox leaf and a bitter yellow sap runs out. Dried, it becomes Cape aloes. Its natural compounds, aloin and other anthraquinones, are why it has been one of the best-known laxative plants for centuries.

1. MedievalAloes is the star of hiera picra, "holy bitter", an apothecary's purging powder of aloes and canella bark.
2. Mid-1700sSettlers at the Cape start exporting the dried sap to Europe.
3. 1842Thomas Beecham starts selling Beecham's Pills, a laxative of aloes, ginger and soap. "Worth a guinea a box" became one of Britain's first famous slogans, and the pills sold until 1998.
4. TodayStill hand-harvested from wild plants in South Africa, with the trade monitored under CITES.

Sources: Cape aloes review, University of Johannesburg · Merriam-Webster · Beecham's Pills, Wikipedia · National Botanic Garden of Wales

Grandma was right. The prune is the kitchen's most famous fix for constipation, and one of the few with clinical trials behind it. Prunes bring fibre plus sorbitol, a natural sugar alcohol that draws water into the bowel.

1. 1100sBy local tradition, Benedictine monks at Clairac Abbey graft plum trees with varieties brought back from Syria, creating the Ente plum behind France's famous Agen prunes.
2. 2011In a trial of 40 people with constipation, daily prunes beat psyllium on weekly bowel movements and stool consistency over three weeks.
3. 2015A randomised trial of 120 adults finds prunes increase both stool weight and the number of bowel movements.

Sources: NutraIngredients, 2011 trial · Lever et al., systematic review · Alimentary Pharmacology & Therapeutics

Rhubarb root holds sennosides. Your gut bacteria convert them into their active form in the large intestine, which is exactly where rhubarb root does its work.

1. c. 1,800 yrs agoRecorded in the Shennong Bencao Jing. As da huang, it became one of Chinese medicine's best-known purging herbs.
2. 1300sTravels the Silk Road to Europe, sold as "Turkish rhubarb".
3. 1542A French price list values it at ten times the price of cinnamon and four times that of saffron.
4. Late 1700sJames Gregory grows rhubarb for the Edinburgh stomach powder that carries his name.

Sources: Journal of Traditional Medicines · Rhubarb, Wikipedia · NPR · Gazetteer for Scotland

Magnesium sulphate is the salt from Epsom's famous bitter spring. In the gut it pulls water into the bowel, softening stool and getting things moving.

1. c. 1618During a drought, farmer Henry Wicker finds a bitter spring on Epsom Common that his cattle refuse to drink. Word of its purging power spreads, and Epsom becomes a fashionable spa town.
2. 1697Nehemiah Grew publishes A Treatise of the Nature and Use of the Bitter Purging Salt from Epsom water.
3. 350 yearsEpsom salts become a medicine-cabinet staple for constipation.
4. TodayStill approved as a laxative in the US.

Sources: Grew's treatise, Texas A&M Library · Wellcome Collection · Apartment Therapy · Magnesium sulfate, Wikipedia