My doctor also uses a 40fr bougie and the way he explained it to me is he uses a 40 to 43 depending on the person then he also stitches over the staples which reduces the size some more. He also explained to me the smaller the bougie the more chances of complications. I also saw a video on you tube about this and really there was very little difference between a 32 and 42 so I didn't worry about it. I am 4 weeks post op and do good to eat 3 to 4 oz of mushy food. I am trying solid food now and that is not going so good I get full so fast I mean 4 or 5 bites and seems the more dense the food the less I can eat.