I don't know how long he has been up but my little one is having a hard time going back to sleep.…

I don't know how long he has been up but my little one is having a hard time going back to sleep. Ive tried feeding and changing him. Ive tried rocking and patting him back to sleep. I have even looked over his whole body and nothing appears to be wrong. The only thing I can think of is gas. I tried burping him but nothing. I feel so bad that he is uncomfortable. He is doing fine in his swing though!