I feel so silly. I took stock of what I've eaten over the past week, and that was fine, but I realized my water intake has slipped again. I eat a lot of fibre (including Benefibre or Metamucil), but the lack of enough water meant that the fibre couldn't do its job. Add to this that I take Ferrous Gluconate due to very low iron and it makes for not a happy digestive system. It occurred to me today when I was feeling bloated and uncomfortable. Things are remedied now, and I will keep this in mind.
It's amazing how one little thing can have such an effect.