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Miralax vs. Kristalose

Polyethylene glycol 3350 (Miralax) and lactulose (Constulose, Kristalose) are both osmotic laxatives used to treat constipation, but they have some key differences. Miralax is available over-the-counter, while lactulose requires a prescription. Miralax typically causes a bowel movement within 1 to 3 days, whereas lactulose usually works within 2 days. Both medications can cause side effects like gas and bloating. Additionally, lactulose contains sugars like galactose and lactose, which can affect blood sugar levels, making it less suitable for people with diabetes. Miralax, on the other hand, is generally considered safe for people with kidney problems, provided a healthcare professional approves its use.