This chapter presents a case study of John, Who is a 54-year-old man who had a surgery for a carcinoma of the colon. Treatment is based on blocking the effects of specific neurotransmitters: Haloperidol blocks central dopamine receptors in the chemoreceptor trigger zone. Cyclizine blocks histamine receptors in the brainstem. Domperidone and metoclopramide block peripheral dopamine receptors in the stomach and upper small bowel. There are 33 randomised controlled trials that support the use of the P6 acupuncture point for vomiting due to chemotherapy, morphine or post-operative nausea and vomiting. If the vomits are large volume and the patient dehydrating rapidly, consider gastric outflow obstruction as a cause. If the vomits are large volume but hydration is reasonable, this could be gastric stasis.