Hello and welcome to HCM.
Thank you for your query.
I can understand your concern. The kidney area you are referring to could in fact point towards a kidney, condition, but could also be due to other structures lying in the same region. Your bowels could be inflamed or irritated, which could have resulted in the blood in your stools. Fresh blood in the stools indicates a lower gastrointestinal (GIT) bleed, and will have to be looked into. Causes could be hemorrhoids,
irritable bowel syndrome, ulcers, polyps,
diverticulitis, etc.
I would also request you to undergo another pelvic
ultrasound to visualize and grade your
prostate, and if required even a
digital rectal examination. If your prostate is indeed enlarged, it could be compressing the
urethra that could cause retention/stagnation of urine, that could result in the
kidney pain and even infections. Although this cannot explain the blood in your stools.
To find out what the chunks you observed in your stool are, you will have to give your stool for analysis to the laboratory. This could be undigested food, parasites, etc.
It is difficult to tell without viewing them or analyzing them in the laboratory. I thus request you to visit your doctor and go about all the above mentioned investigations.
I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications. I would gladly help you.
Best wishes