1999 Honda Odyssey Water sprayed up the tail pipe

My son was rinsing dirt off the back of our van and decided to spray water up the tail pipe. I am not sure how long or how much he sprayed up it. The van was sitting nose down for about 24 hours before we found out this happened. When I started the van, I could hear a odd sound coming form the back of the van to find out water would pour and spew out. Not knowing if this would hurt the running of the van, I took it to town. As I drove, water was pouring down the street for a good mile. On my way home, it seems my transmission started acting up. It started changing hard when changing up or down shifting. The transmission is a one year old certified transmission. Could the water have caused any damage to make it to run so rough?