Anybody else's toddler still not sleeping through the night??

We had a very small period of when our toddler would sleep through the night, but then the hurricane hit, then we were displaced for a week, which messed our schedule up, but then he caught a stomach bug on top of it. It all went down hill from there. He is up at least 2+ times a night some wakings taking over an hour to get him back to sleep. His sister (3) isn't a great sleeper either so we are constantly up and down between both kids at night. Any suggestions on what to do? We've talked to his doctor and they were no help and gave no suggestions. Thank you in advance!