If your husband is just drinking alcohol and not eating, that is probably the cause of his diarrhea. He's not on Lactulose, is he? You can try rc's suggestion or the BRAT diet (broth, rice, applesauce, dry toast) to get it under control. It could be that the ascites fluid is infected. If he would get tapped (drained) they would test the fluid.
Why would you need to go away in order to talk? It doesn't sound like he is in any condition to be going anywhere. However, it's always good to have a talk about his wishes for end of life.
Hugs,
Connie