Hi. Read and understood your problem. The pains are terrible and associated with burping, farting, thumping pulse, vomiting, foamy saliva. The probable reason for such a symptom-complex is gastroenteritis, a waterborne infection. Consult a Doctor as you need to be examined for physical, vitals like pulse, BP, temperature, dehydration, abdominal physical examination to get a proper diagnosis, prescription and an order for investigations if your Doctor feels so. The cause of foaming salvation and vomiting is a reflex whenever the intestines have any problem. The thumping pulse is indicative of dehydration and body s response to keep it going or can be due to hyperthyroidism which in itself may be a reason of gastroenteritis like symptoms. Farting indicated severe infection with bacteria capable of producing septicemia and gases. All these things together cause severe pain in abdomen. IF required get admitted for intravenous antibiotics, antiemetics and fluids to correct the dehydration.