Colon cleansers and laxatives, do these work, what do they do?

For what purpose?: If you're looking for powerful laxatives, i assume you feel very constipated or are looking to "cleanse." if the latter, please reconsider ; check out numerous Healthtap answers that point to problems with colon cleansers--don't use them! if constipation however is new or has significantly worsened, or is accompanied by distension, vomiting, fever, pain then don't self-medicate but get checked.