Beachball constantly appearing
MacBook Pro 13 inch early 2011
2.7 GHZ i7
4 GB RAM
OS X 10.11 El Capitan
A couple days ago, whenever I was just using Chrome or any other applications on my Mac, the beachball started coming up for about 20-30 seconds at a time, in no specific time intervals, sometimes 2-3 minutes in between occurances or even 5 minutes. If I am watching a video on Quicktime, the video and audio freezes for about 10-20 seconds. I tried to see if there was a software problem, but whenever I checked the Activity Monitor, there didn't seem to be any app taking up a significant portion of the CPU. I checked the Console and discovered I got the disk0se I/0 error that seems to occur whenever there is a slowdown in my computer and the beachball occurs.. Have tried using the FIist Aid option in the new Disk Utility, and every time I use it, it claims the drive is completely fixed, but the issue keeps recurring. I can restart the computer and boot up fine, but am continuing to encounter the beachball periodically.
Are there any possible fixes to this issue that doesn't involve replacing a hard drive?
MacBook Pro, OS X El Capitan (10.11)