Hi. Thanks for your query. Noted the history and understood your concerns. Since Cistoplatin is a anti-cancer medicines and has selective actions on cancer cells it still have side effects, one of which you are having. You ave pain in abdomen, burping and gases but no nausea, proton pump inhibitor is not working, nor the tums. This indicates that the problem may be in the small and large intestine and may be due to intestinal infection as Cistoplatin reduces body s resistance. I would advise you the following: Get the stool checked as well as blood for CBC. If there is an evidence of infection, get started on proper antibiotics and probiotics, this may relieve your problems. Coke being an aerated drink can cause more gases. Have boiled and cooled water. Home-made food only. You may also need upper and lower GI endoscopy along with ultrasound if the medical management fails. Take care about the original problem you are suffering from.