Hi, Since she is already diagnosed with H pylori infection, it is necessary that she is put under treatment regimen with an antibiotic such as amoxicillin and proton pump inhibitor such as omeprazole etc. Effects are seen only as the course progressess to completion. Sometimes the antibiotic can cause diarrhoea and vomitting and changing it helps. Since the endoscopy suggests a colon problem it means there may be other reasons for the cramping and diarrhoea such as food intolerence , Irritable Bowel Disease etc. If any of these conditions are diagnosed it means different treatment strategies have to be employed and will help overcome the symptoms. Hope this helps.