Intestinal fluid retention via osmotic effect

The "intestinal fluid retention via osmotic effect" refers to the process by which poorly absorbed or non-absorbable substances in the intestinal lumen create an osmotic gradient, causing water to be retained within the gut. This leads to increased water content in the stool, resulting in softer stools or diarrhea. This mechanism is exploited by several osmotic laxatives (such as polyethylene glycol, lactulose, sorbitol, and magnesium salts) for the treatment of constipation or for diagnostic bowel cleansing. It also underlies some forms of diarrhea—especially when non-digestible solutes are retained in the bowel—by drawing water into the intestine until the osmotic load is removed.

Other names

Osmotic effect in the intestineIntestinal osmotic fluid retentionOsmotic diarrhea mechanism

Increase luminal osmolality to draw water into the intestine by osmotic gradient