Pain on the left side of the belly?

Clinic visit needed: There are many causes of abdominal pain, some of which can be simply annoying, like constipation, others can be deadly. The best way to make sure it's nothing dangerous is to be examined by a health care provider. Most of the time the cause can be determined with a physical exam and a few simple tests. Less often, an imaging study or looking inside the gut with a scope (endoscopy) is needed.

Pretty vague: differential diagnosis includes many conditions, depending on age, commorbidities - it ranges from gastritis, splenomegaly, kidney stone/urinary tract infeciton, small bowel obstruction, diverticulitis, ovarian cyst or rupture. More info is needed to differentiate between these.

Pain: Abdominal may may stem from multiple causes. In females, it is even more complicated. Pain can result from multiple GI conditions including constipation, renal colic, Pyelonephritis, referred pelvic pain, ovarian cysts amongst others. If pain is not resolving or worsens, you should visit your doctor for further evaluation and work up for the L sided abdominal pain.