How Can severe Constipation Along With Vomiting  be Treated?

Hi, I have been experiencing clear phlegm that comes rapidly and makes me spit until I vomit the contents of my stomach. Usually it is accompanied by bowel pain and inconsistencies. I am usually regular with my bowel habits, having a movement every morning. Usually once I vomit I feel much better. I have tried to track my habits but have found no consistent pattern. It could be on an empty stomach, a few hours since eating or full stomach. The food itself is varied as well. Lately, I feel as if I m going to get sick and the feeling may last for an hour then goes away, or I may need to spit phlegm a bit then it s over. This has been on and off for almost a year. I may stop for a month then the next month happen almost daily.