For the last few days, my LO has started making the strangest noises, and I don't know whether its because he is in pain or has really bad wind. I can't describe what the sound is. Its like a donkey moaning? His wee body also goes really tense. He made this noise all last night. We use the Dr Browns bottles and he brings up his wind really well. His burps are sooo long and loud, so I didn't think it could be wind. Does anyone have any idea what it could be?