During last 2 days from time to time i can feel colic in the left side under the rib and also flactulate. it's not strong. stool is ok.should i worry?

Need more history: Have you travelled recently to places with poor water sanitation? Or been eating outside foods a lot? If not, I would let the symptoms of upset stomach run their course for a week or so. If still remains symptomatic, would recommend that you get yourself checked out for a better assessment. Feel good!

Get check up done: May be you are going for viral gastritis which is causing colic or cramping ,you may get diarrhea or it is due to kidney problem .Better get check up done by your doctor if the colic persists .

No, since you are: passing gas, it sounds like you may have ingested food that either tends to cause more gas, such as the bean or cabbage family of foods, or may have a minor problem with digestion of sugars, such as lactose will cause cramping and gas. I recommend seeing your doctor if pain increases, there is blood in stool, or pain persists.