Hi,
I have recently heard a bubble from my upstairs toilet on two separate days this week, both times I have a clog in one of the two upstairs toilets. Is this the cause or is there another reason for this. There is no smell and as far as I can tell there has been no backup into a sink or a bathtub, although I do have one sink in my house that drains slower than any other. Do I need to snake the drain? I am not very knowledgeable about plumbing so any help would be helpful... also is there a chance that dangerous water can come up into the sink?
-Scott-

Let's be sure about this. Have you seen the bubbles in the bowl? Or did you just hear it? I'm asking this because bubbles can be confused with gurgles by the sound.'
Bubbles indicate a blockage while a gurgle indicates a vent problem,
Sooo, did you see the toilet bubbling? Let me know, Tom

I did see the bubble but it only happened after the sink had been running for about an hour with quite a bit of soap being used. I have OCD so this can happen from time to time. My father-in-law told us about a way to check by using a bucket of water. We poured a bucket of water down each of the toilets and the water went down without a problem. Since I plunged both they have been working and I have not seen any more bubbles. But I don't want to ignore this if there is a problem. I don't have a septic tank also, in case that is important. Thanks for any additional help.

Chances are that you had a partial blockage that you caught when you plunged. Sounds like you're "good ta go" Good luck, Tom