Typically the diarrhea or constipation caused by IBS is the result of overactive muscle contractions in the intestines. As they become hyperactive, they move the fecal matter through the tract at an increased rate. Since the feces is moving faster than normal, water reabsorption is disturbed, causing less water to be absorbed by the intestines. This causes loose stool or diarrhea. The exact opposite occurs with constipation. While "IBS-G" is a possibility (as no disease or symptoms are the same in two people) it would still be a good idea to have other tests run to determine what it is not. As IBS is a funtional disorder between the brain and digestive system, the only way to determine if you have IBS is to determine what you do not have. The cramping-flatulence described could possiblity just be a reaction to a food that doesn't agree with you. Who knows, but unless I misunderstood your post, which is possible, I would advise that you, like most people, have the other tests done to eliminate the possiblity of what it could be. If these are all negative, then you more than likely have "IBS-G" or just can't handle a food very well. As a prologue: I am not a doctor. Some of this information could be incorrect, but is close as to my knowledge. Best wishes