I have horrible sulphur burps. i've had buscopan, omperzole, ondansatrol, vomited three times last night. woke up still have it, even worse?

Constipation: All mentioned drugs can cause constipation as a side effect and your symptoms are strongly suggesting severe constipation/ obstruction. Depending upon the time you had your last BM make sure you start with a laxative suppository, such as Dulcolax/enema. If no success seek immediate medical attention as your symptoms are suggesting bowel obstruction.