I Took Dayquil And Nyquil Fairly Regularly For The "crud,"

I took Dayquil and Nyquil fairly regularly for the "crud," complete with laryngitis and cough, for about 3 weeks and ended dosing on New Year's Eve. The following week I began having diarrhea, or the closest thing to it, and it's lasted into the 4th week. Immodium helps a lot, lab stool tests came back completely negative, I have no terrible pain or bloating, it rarely occurs in the evening and never during the night, and I'm just wondering if the Dayquil and Nyquil could be responsible and how long it'll take to quit. My problems usually run toward constipation so this has been highly unusual. I am a 72 year old, healthy female. Any suggestions or comments?