I can't imagine how water generates gas in the intestines (no bacteria break water down into gas) but it may alter stool consistancy and that may change how gas moves in the GI tract...just a guess based on how things work.Have you tried probiotic bacteria suppelements. It may be that this is not IBS but that you had a shift in the colonic bacteria. Different species of bacteria produce varying amounts of gas (assuming that diet is relatively consistant through all this, which it may not be). You get exposed to these bacteria all the time and so the population can change over time. Probiotic bacteria (acidophilus is one common name for these in the store) produce no gas from the digestion of the carbohydrates you do not digest.Now the rumbling after dinner may be a mild kind of IBS. The colon gets more active after meals, and larger meals like dinner usually cause bigger results, so you may be having those issues...and that it sometimes go to diarrhea that may be the mild edge of IBS. Discomfort could include the loose stools being overly urgent, and if you find holding the gas in uncomfortable (rather than just embarassing having to leave the room) that is also in the tending to IBS pile.But you should see the doctor as various diseases/disorders cause GI symptoms and this may be a sign it is time for at least a standard physical to get things checked over. And for woman they should also include a female check up if they haven't had one of those for awhile as some Gyn issues can cause GI symptoms.K.