Going to the bathroom in basement at night

Question
QUESTION: My Yellow Lab is nearly 7 years old now and I have had him since he was a puppy.  He was easily trained with anything I tried.  I also have a 6 year old Chocolate Lab that was a rescue that I got about 4 years ago.  The two boys are inseparable.  My Yellow has never had any issues with "holding it" until recently.  They are walked, plenty of attention, plenty of play time, and generally extremely happy boys.  For the last 3 months though my Yellow has been peeing, pooping, or both in the basement at night.  Nothing has changed in out routines at all.  Before all of this started I think he would rather explode than go to the bathroom in the house.  It has gotten to the point that there is something in the basement nearly every morning.  There are times during the day that he might be alone with my Chocolate for 8 hours or so and there is never accident then...only at night.  Is he just getting to that age that he can't hold it?  The vet said there is nothing wrong with him from the panels they ran.  Please help.  My basement cannot take much more of this.

ANSWER: 7 is too young to start having issues like this. Restrict him to a smaller area with a tether or gates. The smaller the area, the less likely he is to make a mess. Is he by himself down there? Does he spend time down there at all during the day?

---------- FOLLOW-UP ----------

QUESTION: He and his "brother" have always had the run of the house without any incidents before now.  I actually closed the bedroom door so he was in there with me and his "brother" and he peed in there night after night.  I couldn't have the carpet taking that so I opted to figure this out while he uses the basement.  Should I stick him in his kennel at night?  He has not been in it for almost 6 years.

He spends very little time in the basement...only if I am down there doing something.

Answer
It's not unusual for a dog to start using a place that he doesn't spend much time in as a bathroom. Your bedroom is a more unusual choice for a bathroom than the basement. I'd put the kennel in your room and have him sleep in there. Visit http://www.examiner.com/examiner/x-7644-Detroit-Pet-Training-Examiner~y2009m7d29
for tips on how to get him to think it's a privilege.