The skin is the largest organ of detoxification, but it's the last to indicate that the entire system is under load.
One of the key players in the detoxification system is the liver which can become overburdened if too much demand is placed upon it and/or if it's not supplied with adequate resources. I could have mentioned some of the other organs, but your inquiry regarding natural laxatives points at the liver specifically, secondary to down regulation of the thyroid. In an effort not to overwhelm or confuse you with too much information, here's what I'd focus on:
--positive thoughts as health/disease truly begins in the head. Taking 10mins/day to focus on all the many blessings for which you have to be grateful is often enough to put things in perspective so that we realize how good life really is.
--DEEP breathing, focusing on expanding the belly with each inhalation (diaphragmatic breathing as Nature intended).
--hydrating with pure, clean water (the filter I use/recommend can be found here: http://triumphtraining.com/pages/recommendations). Aim for 1/2 your body weight in lbs in oz of water each day (i.e. 150lbs =75oz). Additionally, I'd add some Celtic Sea Salt or Pickling Salt (just a pinch) to each bottle (steel or glass) as it will serve in better utilization of the water while up regulating the thyroid and working as a natural anti-histamine.
--eating clean as possible (see my blog for details as this is a simple but extensive subject), minimizing foods that are anti-thyroid (raw cruciferous veggies, vegetable/seed oils, grains, any foods with added gums or carrageenan, etc). Additionally, I'd eat frequently enough to maintain blood sugar and try to balance the macronutrients.
--moving daily but not in excess. 45mins is a good ceiling for duration unless you have a good reason and good enough health to warrant longer sessions. Strength training is preferable to cardio. And squatting movements will help compress the ascending colon to help things keep moving...
--sleep from 10 p.m. to 6 a.m. to minimize circadian stress.
Stress in all its forms is the main reason why the thyroid becomes dysfunctional. And when it's not working optimally, neither is your system of detoxification or your system of elimination.