Which OTC medications are effective at treating chronic constipation?  Lots of products are effective at treating chronic constipation.  First-line therapy to treat chronic constipation is polyethylene glycol (Miralax) or senna. Other good products are stimulant laxatives, fiber supplementation or magnesium-based products.  Psyllium fiber tends to cause bloating and gas.

I, personally, suggest that patients fiddle with the dose of Miralax and take it (daily) if needed.  Miralax never leaves the GI tract meaning that it does not tax the liver or kidneys and it helps draw water into the intestines to keep the stool soft.  The drawback about titrating the dose of Miralax is that if you take too much (for you) when you pass gas, you can pass stool. 

Live and learn, right?!