In 2002, the Federal Drug Administration banned the further marketing of cascara and aloe-based natural laxatives for treating constipation. This action left senna as the sole herb-based treatment. Senna is derived from a plant that is found around the world, but with origins in the region now commonly known as the Middle East and East Africa. In temperate regions, one can find variations of the senna plant. Its shape is essentially a short to medium height shrub.
The word senna itself has an interesting history rooted in the Semitic languages, as befitting its origins. It's also known by another equivalent name, cassia. Both are commonly used. It's active ingredient is a chemical or a class of chemicals known as the anthraquinoids. Anthraquinones are found in other types of laxatives. They have the effect of stimulating movement in the intestinal tract.
It's quite plausible given what we know about senna's etymological and geographical origins that its use actually goes back centuries. It was used in an unprocessed, essentially raw, form in times past. Nowadays, advanced manufacturing processes allow the herb to be bought in capsule or tablet form. Consumers can also opt for the tea formulation.
Though it's thought of as an herbal treatment, a prospective consumer should be aware of the history and quality of the producing company. Natural laxatives can be dangerous even if they are natural. Prospective consumers should consult with organizations who monitor the quality of such companies to ensure that they have not had serious breaches of business ethics or been embroiled in disputes of quality. Allergic reactions are rare but should be kept in mind.
In line with the issue of safety, one should always know that there are warnings associated with senna usage. For example, it has been noted that people with a history of heart disease or hypertension should refrain from taking senna. In fact, it's important to realize that a patient should consult the advice of his personal doctor before embarking on any laxative treatment, natural or not.
The original method of consumption was in herb form. In modern times, there are many ways of taking senna. A tea form is available from many producers. Application is as simple as dropping a tea bag in hot water and having some tea. More sophisticated forms also exist. The tea formulation may have been the exact way senna was used in pre-modern times.