Why do people go on cleanses?

"Why do people go on cleanses?"

The reason why some people will go on cleanses or detoxes, is they have a high gullibility for WHAT APPEARS to have scientific validity, and yet as per one answer basically doesn't take time to actually fact check the claims, against actual hard scientific research and the results of that research. 

Also the advent of the internet, and more specifically to a large extent, YouTube celebrities, who tout these cleanses/detoxes. The advent of the internet found a new fertile ground if you will, for these things, to once again take root. None of the cleanses/detoxes are actually new, but are being revisited, and those who promote them, are either in it for the money, and/or the notoriety it will get, or will them. All that's done is dress them up with some scientific wording to make them look valid.

So those who know better, are taking advantage of the people who has a high gullibility factor. Those promoting the so called cleanses/detoxes, are very much like politicians and their respective political parties, also preys on the gullibility of people.

Most of the so called cleanses/detoxes aren't made by manufactures, but most are as I stated before old ones, that's simply been dressed up with some scientific wording to look like it's new. Yet most if not all so called cleanses/detoxes, are based on old home remedies, myths, and old wives tales. However most of the items while they're usually available, aren't usually marketed as being used for cleanses/detoxes.

Because of all the misinformation going around and people don't care to fact check anything. Then when people try "detox" things they get symptoms and assume that its because they are detoxing when in reality its because whatever they are doing/ingesting, causes side effects. A good example is that tea that causes diarrhea. The diarrhea is not because your body is detoxing. Its because that tea is a laxative. 

People do these detoxes because manufacturers claim they actually do something for our bodies. Plus manufacturers want to make a bunch of money and pad their bank accounts.

You're right, our liver works to detox our body every day. Even so, there are people out there who eat junky diets and so they walk around with fluid retention, inflammation, leaky gut syndrome and more. "Detox" doesn't help this either, but a natural, healthy diet, does.

All kinds of reasons. 

Our bodies evolved with the concept of frequent fasting. Fasting and cleanses also help to clear out our GI system. Especially the large intestine and the colon. And reset the biome in our guts. Water fasts help clear out the kindneys and liver of toxins that build up over time. And help shrink some of our fat cells. 

Because the placebo effect and the different physical feelings brought about by consuming nothing but liquids dupes them into thinking they're getting healthier and ridding their bodies of toxins, when in fact their liver and kidneys already do that just fine.  If their bodies were full of toxins they would be seriously ill and need hospitalization.

Because none of our lives are normal anymore, if by normal you mean natural or anything within shouting distance of it.

We are being exposed to a myriad of chemicals that have never existed in the past. Our bodies aren’t equipped to deal with all of them. Remember DDT? You can’t bathe in DDT and expect your liver to take care of it.