No. I never use the plunger, even for water. Just pour and go! No back up, no problem. That's what they even did in the hospital. Once in a while I used the plunger, if it backed up, but wasn't frequent, maybe more from meds. I'm also not tube dependent now, but was for several treatments. I used a coffee grinder to crush the meds to dust, then mixed with water, poured into the tube, flushed. Not all meds should be crushed, like pain meds, so check with your pharmacy or ask for liquid medications. I refrigerate mine because that's what my infectious disease doctor said to do for storage, but never asked why, and assume it had to do with bacteria? I've had this peg, button type, since December 2010, although I had one before that, which I had it yanked out after being NED in July, 2010, and a month later had a recurrence, had another one put in, and kept it since, and used it for several treatments. The peg saved my life, initially losing over 110lbs in 2009, and have gained 50lbs back, actually 70, but lost, gained, lost since last summer due to treatmnts, and teeth issues. Some wanted to take the tube out, but my local oncologist understands my reason for keeping it having been with me through my worst tmes, and possibly needing it again.