I had two obstructions in the past, the symptoms were extreme pain coming and going in waves, no gas, and finally vomitting. Sometimes you hear loud noises coming from your intestines, it's because the gas cannot pass through the obstruction. If it's only a partial obstruction, then you may be able to pass some gas or have d, but still very painful. You will know that it's time to go to the hospital, which in my opinion is the best you can do, because obstructions usually do not pass on their own, you need medication and pred.
Hope I helped,