I do not think this is the problem. Currently I am unable to eat anything at all due to a surgery i had. I have been on a liquid diet. Water, soups, milks and juices if the acid level is not too high. Anything more and there is severe pain in my throat and mouth. Sometimes even a drink will hurt. The only good thing is I am currently losing almost 1 kilo per day in body fat.
Yet, I poop daily albeit mostly liquid comes out. I think he just needs to adjust diet. his body should eject the waste no matter what it is he eats or drinks. All these things people are telling you. Work for some but not for all. You should have yourself checked with doctor first. If everything is normal in your body then I would not worry about the amount of times you are pooping.