If you had no colon. Food leaves you 4 hours or so after you eat it.No absorbtion of nutrients occurs in the colon, it isn't broken down any more into more digestible bits there or anything like that. So by 4 hours you have had all the time you ever will have to absorb the nutrients. Whether or not it spends 1 minute, or 3 days hanging out in the colon.Now some people do get responses in the colon that causes it to dump fast (like often eating the next meal will cause the colon to dump) Any food you didn't chew enough that ends up in the colon in recognizable pieces comes out of the colon the same way it went in.Looser stools makes it easier to see this, but even people with 100% totally normal stools and digestion if you look at the stools closely enough and disect the compacted stuff apart will have recognizable bits of undigested food in it as long as they eat anything with fiber, or shape to it. (like corn...you don't chew it up enough it comes out of everyone pretty much the way it went in...even if you chew it well the outer husk goes through unchanged no matter how many hours it is in there).No food is ground up by the colon.Mostly all that happens in the colon is water absorption.If you take your standard run of the mill IBSer and test them their levels of nutrients in the body reflects what they eat. Anemia or other signs of mal-nutrition is a sign that SOMETHING OTHER THAN IBS IS GOING ON.Small-intestinal issues (like celiac) ARE NOT IBS.Now do people get mis-diagnosed, yep, but that doesn't change what happens in pretty much every single person who is correctly diagnosed.AND that doesn't change that NORMAL people with NORMAL stools have undigested bits of food they didn't chew well enough and that by 4 hours after you ate it you have absorbed all you are going to from it.People without colons absorb all the nutrients from their food JUST FINE.IBS does NOT include every person with every GI problem on the planet. Really, it doesn't.AND one problem with food intolerances is the brain. If your brain knows that Spinach for instance makes you sick, sometimes it will make you sick if you eat it because it has been conditioned that way. Even if there is nothing actually going on in your immune system. REALLY. Raisins make me sick, but it is because I ate raisins once when I got sick for some other reason and now they bother me (well actually I think I have finally broken the connection in the brain and only now have been able to eat them again, but I had to avoid them for years to break the brain's conditioning that raisins are the great evil and must be expelled immediately (I usually vomited them up rather than diarrhea--but the same mechanism works) VERY often if you feed someone something that routinely makes them ill if the KNOW they ate it, but hide it so the brain never knows they ate it, they don't get sick. That adds a whole level of complexity to the food intolerance issue. Some of it has nothing to do with the immune system in your small intestine.K.K.