Sirius is Sick Again

I was up with him all night. From 9:30 -3 am he threw up 10 times. Usually two or more each time he felt sick. From 3am -5 he rested much better, but still had to go out side to potty. Liquid where there should be solid, not nice. Still dealing wit the potty issues this morning, but he hasn't thrown up since 3 am, we're closing in on 12 hours. he's had a cup or so of kibble and water since about 9am, and kept it down, But he can go 3-4 hours before puking it back up, so I'm not ready to party quite yet. Right now he's rough housing with Zeus. Earlier he launched himself off the deck to chase the birds from our yard - he's not acting sick. But he might not be as peppy as usual - although he was up all night throwing up. I wouldn't be ready to wrestle either. I switched him back to tap water yesterday. Even though tap water shouldn't cause this, it's looking more and more like the culprit. When he got sick two weeks ago, I started using filtered water. My plan was to take away anything that could cause an upset, add gentler alternatives. He had tap water Sunday, and threw up - both times he drank it. Added tap water back in yesterday, and he had more than he did Sunday. Was sick all night. Filtered water today, so far so good. Makes me afraid to use it. Could it be my pipes? Could it be all the rain we've had recently? I have no idea, and Dr. Rambo has no answers for me - he says it's weird, but it is my dog we're talking about. So, the next step, the one I fretted over two weeks ago, doc wants x-rays. He's looking for anything that doesn't belong, and checking for mega esophagus. This is what there's no money for. Finding answers. This is what I cried over two weeks ago. This is what I'm praying over now.