First, thanks everyone for your thoughts and prayers. Update - my FIL had a minor stroke. It appears he did have a blood clot that separated in his brain (since they checked his lungs because of his breathing problems I guess they didn't check his brain). The doctors believe he will make a full recovery, thankfully. We just don't know when he'll be able to go home or if he'll need any rehab. And they don't know why he has fluid in his abdomen, but since there are several small pockets instead of one or two large ones, they can't draw the fluid out easily.
My stepdad was about 65 when he had his first stroke which he recovered from almost completely and my FIL is 69. Continued prayers and thought are requested because he could have additional strokes from this point, as did my stepdad. And those aren't easy to recover from.
Welp. All the talk (and minor changes) that my husband and I have had the past few years about our eating habits and need for exercise was once again brought home. I think he might finally be totally on board for change.