Lagolax Oral Solution Powder contain macrogol 3350, is the oral osmotic laxative which promotes the retention of water in the bowel, thereby increasing the water content of stool, which results in increased gastrointestinal motility and stool transit time and evacuation of colonic contents. Macrogol 3350 is also known as polyethylene glycol (PEG) 3350. It works by draws water from the rest of the body into your bowel to make your poo slightly bigger and softer. It then triggers your bowels to start working to push the poo out. Hence it can be used as a medication to treat constipation in children and adults.