Thanks for posting your query.
With the available described symptoms, there could be possibility of decreased gastrointestinal motility which may be caused by thyroid hormone deficiency
may also cause fatigue, tiredness
and joint pains
by increasing weight.
You should again consult with your treating doctor or internal medicine specialist and should go for thorough check up.
You should go for thyroid profile, if not gone previously.
As such there appears to be least chances of diverticulosis
or any colonic pathology.
You should consult with dietitian for dietary change advise.
Meanwhile, you should continue exercise as much you can do.
You should also take prokinetics and high energy supplements for correction of tiredness.
Dr. Mayank Bhargava