constipation, drug induced
"I have Fibromyalgia, IBS-C,  & worst of all, OIC. I took as prescribed one day.I got horrible pain and withdrawal symptoms, Gut gurgled for a couple hours in the morning. Then Zip, Nada, Nothing!!  I was out after that. 2nd day too sick.  
I thought I should give it a 2nd try 2 wks later to make sure as I had high hopes I might get back some of my life. Same again but worse. Kept repeating symptoms at odd times for 4 days so far. I dread reliving withdrawals at bedtime. 
Docs should know Fibromyalgia is brain related disease so the med is crossing the blood barrier."