Bisacodyl
"This stuff is amaaaaaaaaazing.  I had gastric sleeving nearly 12 months ago and I was constipated before surgery but way, way worse after surgery.  I had tried every product on the market and was still constipated.  I bought some of these little beauties in Thailand on holiday and it worked a serious miracle.  I may be the only person who can holiday in Asia and not get the squirts.  Not sure whether the preparation is the same in Australia but I will be stocking up next time I go on holidays.  Best.laxative.ever."