Hi, this whole flat stools means cancer got me in a real bother in the last few months. I was convinced I had bowel cancer or something sinister there was no other reason why I would get flat stools. Although I am a known IBS sufferer. I wouldn’t let it go until my doctor caved in and decided she would treat me a new patient and started the typical IBS symptoms testing (in my defence I was diagnosed at a young age and doctor admitted there was nothing on my records to confirm it) I had my first feacel Calproctin test to determine any inflamtion and it came back high and needed to be repeated. Really got worked up and was worried and doctor was still convinced it was due to medication I was on that this was high I was convinced it was something more.eventually retested and guess what it’s all normal, no inflammation what so ever to indicate there couldn he something sinister happening in bowels. So as everyone says this flat stools can just happened and doesn’t have to mean it’s something sinister. I hope this helps.