Tmi- Diahrea?

Last night my belly felt a little funny then all morning through now I've spent on the toilet with incredibly watery stool. I haven't changed my diet and don't feel nauseous so I don't think it's food poisoning. I googled it and some sites say it's a sign of preterm labor.. Eek! Has anyone else had this or know what to do to treat it? I haven't had even Braxton hicks so I doubt it's labor but I am still concerned.