Hi Michelle, Yes, severe abdominal pain may be due to kidney stones. Region of pain depends on Location of stone in urinary tract. - Uncomplicated kidney stones located in kidney may be asymptomatic or give mild dull aching pain over right or left upper abdomen depending on site of stone. - Stones in ureter which is a tube connection kidneys to urinary bladder (urine bag) give severe pain in back radiating anteriorly to abdomen. It causes more severe pain. Region of pain varies vertically depending on position of stone in ureter (upper, middle, lower) - Lower abdominal pain may be due to stones in lower ureter or urinary bladder. Usually stones in urinary tract may associated with infection (UTI) or blood in urine. (Though UTI in the absence of structural abnormalities in urinary tract ase more common in female.) In your case I want to know - 1) Depending on what basis your doctor told you the presence of stone. 2) Any associated symptoms like nausea, vomiting, loose motions. 3) Any menstrual complaints (considering you as a female). Following investigations may help in locating the site of stone in urinary tract if present- 1) X ray KUB. 2) Ultrasonography of abdomen and pelvis. 3) Intravenous pyelography it helps in establishing site of stone as well as kidney function. Green color stools in your case may be due to- 1) Antibiotic use for UTI. 2) Intestinal infection (it may usually associated with multiple episodes of loose motions, vomiting, central abdominal pain.