Running Ailments

My running partner has been suffering from a "side stitch" on almost every run. I've done a little reading on the topic and understand it might have something to do with your right foot hitting the ground at the same time as you inhale, or possibly several other stride/breathing related issues. Does anyone have a good remedy to the problem? Should she be more concerned? She's trying to run through it but it is sometimes so painful she must walk.