I know it's difficult to get motivated to do things (simple things) when you're so tired. At times I have to force myself to get outside and take a walk. Or go outside and just read. The house for me gets depressing. Anyway, I never regret doing those things once I get started. I think the natural endorphins (feel good hormones) are released and it helps suppress some of the bad feelings.
As far as the IBS goes, I'm learning I have all of the classic symptoms of fibromyalgia (FM). I fit the symptom profile so well it's frightening. I'm hoping that I can get to the bottom of the cause with a goal of eliminating medications, tests, doctors, and frustration. I purchased a book written by a family practitioner with FM. She developed a plan that worked for her; so I'm going to try it. It's mostly diet, exercise and emotional work. It was only $15 which I've spent on 1 lab test.
Hopefully, my doctor office will call me with the results of my serotonin and cortisol tests. I'll probably call on Mon or Tues if I don't hear from them.
Hope you are feeling better. Keep me updated with how you're doing!