I saw a couple of things that had the don't take laxatives too much thing about it, but I did a bit of research on this laxative induced cathartic colon thing and found this info. It sounds like most of the things that caused that have been taken off the market. Title [Side effects of laxatives] Author M�uller-Lissner S Address Medizinische Klinik, Ludwig-Maximilians-Universit�at M�unchen. Source Z Gastroenterol, 30(6):418-27 1992 Jun Abstract The side effects of anthraquinones, diphenylmethane derivatives (e.g. bisacodyl, sodium picosulphate), saline laxatives, lactulose, and cisapride are discussed. When taken in recommended doses, no relevant side effects have been observed, except for hypermagnesemia following magnesium containing cathartics in renal insufficiency. This holds also true for the time of pregnancy and lactation. (Pseudo-)melanosis coli is characterized by pigment loaded macrophages without apparent functional consequences. It occurs mainly after anthraquinones, but to a lesser degree also after diphenylmethane derivatives. Clinically relevant side effects of the above laxatives have been published exclusively after excessive dosing. They consist in electrolyte disturbances (mainly hypokalemia), metabolic alkalosis, renal tubular dysfunction, and other less frequent side effects. Cases of "cathartic colon" have not been published during the last decades. It was probably due to laxatives which are no longer used. And the same crew published this, but the abstract nor the article is available on the web, but any library should be able to get the article for you.�� �Title What has happened to the cathartic colon? Author M�uller-Lissner S Address Abteilung f�ur Innere Medizin, Krankenhaus Weissensee Sch�onstr, Berlin, Germany. Source Gut, 39(3):486-8 1996 Sep