How much should i worry about abdominal swelling?

Yes, worry about it: Is your distension acute, &/or associated with fever, nausea, vomiting, bleeding? If so, please get medical attention now. If, on the other hand, associated with painful constipation then consider possible c-ibs. Medical evaluation under the rome 3 criteria can exclude obstruction, ileus, ischemic disease, tumors, dysmotilities of the gut, rectal dysfunction. Urgency of care depends on the cause.