Diarrhea

Ever since I picked up another job I haven’t had much time for myself and every chance I get I eat in little portions. I’m not eating the healthiest diet but I’m also not the worst. However recently (3 weeks) I’ve been waken up to having the urge to do diarrhea. Is this because I eat at night right before going to bed? I usually wait 30 minutes or so before sleeping but I don’t even eat that big of a portion, maybe a bit of potato salad or a half a sandwich.