My 18 month son has started throwing the worst tantrums since the arrival of his little sister a week and a half ago. These are all out on the floor screaming to no end tantrums that are sparked by the most insignificant things. The latest one this evening lasted 45 minutes until he finally fell asleep on daddy's lap. He huffed and puffed to the end, though. These tantrums are truly inconsolable and really frustrating to me and my husband since we just don't know what to do. Putting him in his room to cry it out is all that we've been able to do, but he is a little on the young side (I think) to truly comprehend the "time out". Is this just a phase that anyone else can comment on and/or give some pointers on how to handle? Also, on the day of arrival home with Little Sis, we all came down with a GI bug that put us all out for 72 hours to add more stress to our little guy's system. I am feeling so guilty for throwing his whole world upside down right now.