Editing Enema (section)

====== Water-based solutions ======

Plain water can be used, functioning mechanically to expand the colon, thus prompting evacuation.

[[saline (medicine)#Normal|Normal saline]] is least irritating to the colon. Like plain water, it simply functions mechanically to expand the colon, but having a neutral concentration gradient, it neither draws [[electrolyte]]s from the body, as happens with plain water, nor draws water into the colon, as occurs with phosphates. Thus, a salt water solution can be used when a longer retention period is desired, such as to soften an impaction.

[[Castile soap]] is commonly added because its irritation of the colon's lining increases the defecation urgency.<ref name=Safety_and_effectiveness>{{cite journal|title=Safety and effectiveness of large-volume enema solutions |author1=Marilee Schmelzer |author2=Lawrence R. Schiller |author3=Richard Meyer |author4=Susan M. Rugari |author5=Patti Case |date=November 2004 |journal=Applied Nursing Research |doi=10.1016/j.apnr.2004.09.010 |volume=17 |issue=4 |pages=265–274|pmid=15573335}}</ref> However, liquid handsoaps and detergents should not be used.<ref name=Biology_Online_Dictionary/>

[[Glycerol]] is a specific bowel mucosa irritant serving to induce peristalsis via a [[Osmotic laxative|hyperosmotic effect]].<ref name= Glycerol>{{cite web |url=https://www.drugs.com/cdi/glycerin-enema.html |title=Glycerin Enema |publisher=Drugs.com |access-date=2018-09-09}}</ref> It is used in a dilute solution, e.g., 5%.<ref>{{cite journal |vauthors=Bertani E, Chiappa A, Biffi R, Bianchi PP, Radice D, Branchi V, Spampatti S, Vetrano I, Andreoni B |title=Comparison of oral polyethylene glycol plus a large volume glycerine enema with a large volume glycerine enema alone in patients undergoing colorectal surgery for malignancy: a randomized clinical trial |journal=Colorectal Disease |volume=13 |issue=10 |pages=e327–e334 |year=2011 |pmid=21689356 |doi=10.1111/j.1463-1318.2011.02689.x |s2cid=32872781}}</ref>