http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=983&top=4 you can check this link for the official information, here it is written that they usually take 4 weeks for next step after medical results upload, but this is the approximate time they mentioned, I am a Pakistani citizen and here some of my friends got their passport requests just within two weeks after getting medicals done. So, CIC usually take the less time they mention on their website for the process. The column "review of submitted documents" is for their processing about the documents they request you to upload for your online applications. You just need to scan the documents they request you and upload, then the status of that column will change. Normally this column have status of "No additional documents are needed at this time"
But when they need some documents they change it to "We need documents from you" and when you provide them the documents requested they will change it to "Provided" and then later it will change it to "Received" which means you have provided the correct document they want. If nothing is written on that column status then it might be a glitch, you can send inquiry to CIC form "report a technical issue" in the top panel of your online account. Always hope for the best.