Plumbing problems

It's not a good thing when you run the dishwasher and it backs up into your bathtub. My husband was snaking, and plunging for hours to no avail. Looks like we will have to call a plumber in the morning. We already know that we need a new drainfield for our septic, but he says that this problem has nothing to do with that. He insists there is a blockage in the pipes within the house. In a few days I am leaving for a short vacation with my sister, but my husband will be home to deal with the problem, though I hope it will be fixed before then.