A pinching or piercing pain on lower left abdomen accompanied by lower back pain, what could it be?

Pain: It may be related to your bowel or your kidney or it could be fibromuscullar.if it does not go away you may need to see a doctor to get a definitive diagnosis

Acute Or Chronic?: Twenties male w. "piercing/pinching" left lower abdominal pain w. low back pain. If acute & intolerable, then renal calculus, aka kidney stone, or intestinal hernia considered. If chronic & ongoing a sacroiliac joint disorder with pain radiation possible. Severe pain, fever, vomiting, painful abdominal or groin lump & blood in urine indicate need for urgent evaluation. Otherwise see Osteopath.