One thing that gastroenterologists know about is stool. But, I'm not referring to that kind of stool in this post. Follow along. When we do a colonoscopy, for example, we are relying upon stool, or more accurately a stool, as in a three-legged stool. This metaphor illustrates that the three legs must be equally strong or the stool will not stand. The three pillars of support that a colonoscopist needs include: Knowledge Skill Judgment As the gastroenterologist guides the colonoscope along your long and winding colon, he may discover a lesion. He needs knowledge to identify the intruder. Is it a cancer or a benign polyp? Could it be Crohn's disease or some other form of colitis? Is it a normal structure that simply appears atypical? The more experienced the gastroenterologist is, the more likely he will be able to identify the abnormality. But, every gastroenterologist, regardless of experience, confronts lesions he has not seen before. The gastro specialist must have the requisite technical skill, not only to perform the colonoscopy properly, but also to manage any lesions discovered. Removing colon abnormalities requires an assortment of techniques and instruments. What good is having the knowledge that can identify a lesion if you don't have the skill to remove it? Would we permit a cardiologist to perform a cardiac catheterization on us if he couldn't insert a stent if a narrowed artery was discovered? Most importantly, the gastroenterologist needs judgment. In my view, this leg of the stool is what distinguishes good physicians from truly seasoned medical professionals. Medical judgment, in my judgment, is much more difficult to learn than knowledge or skill. By definition, judgment is subjective. There is no medical bible to consult that can confidently advise what constitutes the optimal judgment in a particular circumstance. There are so many variables. This is why a patient could consult several specialists regarding a medical issue and receive differing opinions, all of which might be "correct." The facts don't change, but the physicians' interpretations of those facts and consideration of the overall medical context, may lead to opposing recommendations. One physician might advise repair of a hernia which is causing discomfort while another may counsel against it because the patient has severe emphysema and has high operative risks. Consider how many U.S. Supreme Court decisions are decided in 5 to 4 votes. The facts are the same for all 9 justices, but their decisions often vary profoundly. Two hours before writing this, I performed a colonoscopy. I discovered a medium sized polyp right at the very end of the colon at the spot where the appendix is connected. I had knowledge of the lesion and had the skill to remove it. But, I was concerned that resecting it -- a simple task I've done for decades -- might cause a complication by injuring or puncturing the appendix. Primum non nocere, or first, do no harm, is medicine's sacred mantra. Perhaps, another gastroenterologist would have removed the lesion without any consequence. His patient would not need any surgery to remove the lesion, as my patient might. The patient will return to my office in a few weeks. I thought that he was entitled to a sober discussion of the options while he was awake and alert, rather than sedated on a gurney. Michael Kirsch, MD, is a gastroenterologist who blogs at MD Whistleblower. This post originally appeared on KevinMD. Source