Pain and distension. First comes abdominal pain followed by abdominal swelling + tenderness. Then vomiting of stomach contents followed by greenish (bile)vomiting. May feel like passing flatus, but cannot + bowel movements will cease. Abdominal sounds will be absent due to ileus. Plain abdominal xray will demonstrate distended bowel loops with "air fluid levels. See dr. For severe pain, abdo distension + green vomitus.
Bowel obstruction. Bowel obstruction, like its name suggests, means that part of your one-way gastrointestional tract is blocked. This means you will have constipation, greenish vomit with digested food (because the food cannot pass through your tract), pain in your belly and also might cause your belly to look like it is swelling. If you cannot pass gas, pass feces and you see the signs above, see your doctor.