Some authors say that when you have bowel problems like IBS some people try to keep eating because it seems to help them to be regular and suffer less discomfort since it forces the bowel to keep moving. But after a while it may overload the digestive system and cause more problems. It may be not a case here.
The typical symptoms of IBS are: abdominal pain, excessive wind, bloating, constipation, diarrhea, mucus in stool, etc etc. without any more serious problems. It's basically a disorder of the muscular walls of the bowel so your bowel moves not the way it should (too quick, too slow, etc).