I'm going to wrap up the tour of the lower GI tract, how about that, before lunch. So we'll start with colon cancer, actually colorectal cancer, and the reason we put in that extra term is that there's some biologic and clinical differences between rectal and colon cancer that are pretty important. We don't have time to get into that today, but colorectal cancer, one of the most common cancers in the U.S., and the lifetime risk for an individual is about 5 percent. You saw this slide before in Dr. Coyle's presentation. This is the so-called adenoma to carcinoma sequence, where we go through a series of steps, typically because of accumulation of different mutations. We often will, a patient will tell us they have a history of polyps, and we'll say, okay, well, what kind of a polyp was it? And they typically respond and say it was benign, and that's not really the point. Most polyps are benign. What we want to know is, is it precancerous or adenomatous? So, you see on the left-hand part of the slide, adenomas, those are precancerous, by definition neoplastic. As they get closer to cancer, the dysplasia goes from low-grade to high-grade, and then you get a malignant polyp, which is still potentially curable by endoscopy. And then finally, as you heard, invasive cancer, when it's starting to go into the muscle. That's not something we can take off endoscopically. Medical presentation, most of the time, is asymptomatic. You hope that that's the case, because when they have symptoms from cancer, that typically denotes a more advanced stage. So, if they develop signs or symptoms, such as bleeding, that's certainly something we would have to investigate. And uncommonly, but most ominously, are the emergency presentations. Obstruction where the cancer's completely blocking the bowel, that's still potentially curable, but peritonitis means the cancer's eroded through the bowel, now into the peritoneum where they're getting stool into the belly. That's advanced stage cancer. Bad deal. So, screening. One of you mentioned earlier, you already recognized the guidelines have changed. We're now recommending that you start screening at the age of 45. Anyone here got a 45th birthday coming up? Dr. Hopsin wants to talk to you later. So that's routine screening. That's everyone. That's average risk patients, because, as again, one of you alluded to earlier, we're seeing an epidemic of young onset colon cancer, devastating. So we want to find this before it's advanced, and we want to cure it. Now, in addition, if you have a family history of colorectal cancer, if you have inflammatory bowel disease, especially with a concomitant liver disease called PSC that's high risk, or if you have inherited colon cancer syndrome, those people may need to be started very early, potentially even in their childhood years. Different ways to screen for cancer. Ignore the fact that we're gastroenterologists, colonoscopy is the best way to screen for colon cancer. For patients that won't get colonoscopy, there's other options. Fecal blood testing, excuse me, FIT, or fecal immunochemical test, or now combined FIT plus stool DNA testing. FlexSIG is actually studies show that it decreases the risk of colon cancer, but one of my colleagues made the analogy, that's like doing mammography on one breast and not the other. So really, no reason to do FlexSIG for screening for colon cancer. It can be colonoscopy or one of the other tests. Ladies and gentlemen, this is the enemy. This is colon cancer, various endoscopic appearances. When you see this, obviously there's no doubt that there's something wrong there. We do biopsies to confirm that it's cancer. Try to make a sense of whether it's invasive, which needs to be referred to a surgeon, or that lift sign that Dr. Coyle showed you, that it's not invasive, maybe we can take it off endoscopically. If it's localized, either remove it endoscopically, simple outpatient procedure, low risk of complications, or if it's invasive but not metastatic, then it could be cured surgically. So you find here's a tumor in the sigmoid colon, surgeon cuts out that pale part, attaches it together in what's called an anastomosis, and the cancer should be cured if it hasn't spread. If it has spread or high risk for spreading, then we would typically do chemotherapy. This slide is a little bit outdated. It suggests that when chemotherapy doesn't work, you send the patient home to get their affairs in order. We now have this exciting class of drugs called checkpoint inhibitors, or immunotherapy, that really is changing the natural history of this and other advanced cancers. Just a study presented at the cancer meeting a couple months ago, a small number, I think 18 patients with advanced rectal cancer, that all 18 were cured, at least through the duration of the study, by immunotherapy. So another pretty exciting treatment in the middle there. So we'll leave cancer on a positive note, and we'll go to lower GI bleeding. Strictly speaking, lower GI bleeding means anything that's not upper GI bleeding. And the landmark is the ligament of trites where the duodenum curves around and turns into the jejunum. I like to think about lower GI bleeding as colonic or maybe very distal small bowel bleeding, and you heard a lecture earlier about small intestinal bleeding, which is a different animal in terms of the way we investigate it, the kind of diseases that cause the bleeding. So lower GI bleeding symptoms, very important clinically. Hematokizia means either bright red blood or maroon blood per rectum. Most of the time that's a lower GI source of bleeding. Melanoma, which is black tarry stools, most of the time is upper GI bleeding because the blood has had time to be digested. So the black tarry blood is the digested blood. About 10% of lower GI bleeding presents with melanoma. That would be upper colon with slow transit, giving the blood time to be digested. And about 10% of the time, hematokizia is from an upper GI source of bleeding. Bleeding so much that it's going through the bowel rapidly, coming out red. Those patients typically would be unstable, so you know something's going on. Other symptoms could be related to anemia, like lead-headedness or chest pain. So here are some cool pictures. Over left is diverticulosis. So the hole in the middle, this thing doesn't want to move, the hole in the middle is the lumen. That's what we're looking for when we're pushing a scope through. The smaller holes on the top are the diverticula. Sometimes this is so advanced that the diverticula are as big as the lumen, and you're trying to go through with a scope, not sure exactly which door you should be entering. So that can be a little bit daunting. We'll talk about diverticular bleeding in a minute. The vascular lesions, angioectasias, that look like that big red tuft of capillaries that can sometimes bleed. The middle slide there is ischemic colitis. You notice how that's got a purple, dusky appearance? That's because the blood supply's been interrupted. It's not healthy and pink. Pretty characteristic when we see that. And then finally, hemorrhoids. So now you saw the picture of the retroflexion in the stomach. We can do the same thing in the rectum. When the scope's in there, turn it back around, look at just the inside of the rectum and those little bumps next to the scope are hemorrhoids that obviously can sometimes bleed. On the bottom, cancer, IBD, which you've seen. Sometimes infection can cause bleeding, or sometimes we cause the bleeding. Take off a polyp. Dr. Coyle told you sometimes that when that ulcer heals, it'll then bleed a week or two later. So post polypectomy bleeding. Management pretty similar to the upper GI bleeding you heard about earlier. Two large-bore IVs, because we want to be able to give these people blood quickly if they get unstable, and then manage their volume. Keith, we probably should update this slide. NGD lavage went out about 30 years ago, so we'll ignore that part. But if we have any concern about upper GI bleeding, upper scope first. See if there's anything going on in the upper GI tract. If it's bright red blood per rectum, the patient's stable, no abdominal pain, vital signs are completely normal. Most of the time, we'll go straight to a colonoscopy. EGD would be if there's uncertainty, whether it's an upper GI source of bleeding or lower GI. So if we do colonoscopy, so upper left is a picture of a little bit of a stalk where someone removed a polyp, and now there's blood coming from the stalk. And you can see there, the clip put around the stalk, pinch off that blood vessel, the bleeding stops. On the bottom, so you've probably heard of diverticular bleeding. It's one of the most common causes of lower GI bleeding. Almost always a diagnosis, a presumptive diagnosis. Lower GI bleeding, we scope, we see diverticula, we see nothing else. We presume the diverticula were bleeding. Occasionally, you actually see bleeding coming out of a diverticulum. If you do, you can treat it with clips, but that's uncommon. Other options would be to inject epinephrine. As you know, that causes vasospasm. That can be enough to just stop the bleeding. Sometimes, though, when the epinephrine wears off, the blood vessel opens up again and it bleeds. So typically, we do something in addition, like banding or cautery or clips. The argon plasma coagulation on the bottom, typically used for superficial things like angioacasias, and we'll get a chance to play with that in the animal lab. So that's lower GI bleeding. Diverticulosis, very common. It gets more common as we age. I'll show you a picture. Diverticulosis is pathologically due to what's called penetrating blood vessels that go through the wall of the colon to provide blood. That presents a little bit of a weak spot in the integrity of the wall. Over time, the pressure inside the colon can cause the mucosa to kind of pooch out. That's a scientific term, pooch out, and that's what you see with the pouches here. Almost always asymptomatic, but a small percentage can either bleed, or if the opening of the pouch gets blocked, like by stool, then you get bacteria in stool trapped, and that can turn into an infection, and that's diverticulitis. Pretty common to confuse those two. They're very different conditions. Diverticular bleeding, diverticulitis, very different, typically don't occur together. So if you did a barium x-ray, this is what the little clusters of grapes look like on barium x-ray when the barium goes into the pouch, and again, on colonoscopy, which is the most typical way we would find it. You see these little holes in the wall of the colon. We talked about these two. I can move on. So diverticulitis, again, a diverticulum gets blocked. It's stool, and bacteria get trapped. They fester, turn into an infection, or a frank abscess. That can affect up to 25% of patients with diverticulosis, so you watch for it. Typical symptoms would be left lower quadrant pain, typically severe, with fever, and if you do blood work, an elevated white blood cell count. If you're not sure about the diagnosis, CAT scan would be a gold standard. You see this inflammation in the circle there, which is surrounding an infected diverticulum. Treatment depends whether it's uncomplicated or complicated. Uncomplicated diverticulitis in a healthy person sometimes is even managed without antibiotics. Typically we would give oral antibiotics, follow them closely, make sure they're getting better. If they're pretty sick, if they have an abscess, they typically are hospitalized, IV antibiotics, drains, and then sometimes surgery to remove the involved area. Here's that picture of the penetrating arteries. You see that at the bottom there. That little spot where the blood vessel goes through is just a little bit weaker than the rest of the wall and provides an avenue for the mucosa to pouch out. Again, upper left is a picture of a clip about to be deployed on a blood vessel in a diverticulum. Sometimes a patient's bleeding and they don't stop, and we can't find it or fix it endoscopically. Next step would typically be to send them to radiology. And going through angiography, they can get to the bleeding vessel and inject some coils or other material to make the blood vessel clot off. And then occasionally, not very often, they need surgery. Veins are normal. Part of that tissue down in the anal canal is veins that provide some cushioning as the stools come out. That's normal. What's abnormal is when they get enlarged and they start to protrude out. That's what we think of as an internal hemorrhoid. Or on the outside, if the veins there get engorged, that's an external hemorrhoid. The causes are anything that increases pressure in the abdomen that's transmitted down to the... I didn't come up with these pictures, by the way. So if you like to read a novel when you're on the toilet, you probably shouldn't do that. That predisposes to hemorrhoids and other things. Constipation is a common cause. So if we treat constipation, we can prevent hemorrhoids, straining, pregnancy, and then uncommonly pelvic tumors. Anything that puts pressure down in the vein, venous drainage from the anus. Sometimes they're big enough you can diagnose on rectal exam. Sometimes you need to peek in with something called an anoscope. Sometimes we can diagnose them on colonoscopy. Treatment would be to avoid the things that exacerbate them, like straining, like sitting on the toilet for a long time. If there's irritation down there, it's hard to get the bacteria completely off them after patients use the bathroom. So sitz baths can help keep it clean. If it's really bothersome, we can ban them either endoscopically or surgically. And that's it. All right. Questions for Dr. Farhadi? Where's lunch? Did I hear someone say, where's lunch? Awesome. So one thing you've heard, just to clarify, a couple times today, itis, itis, itis, itis, itis. Itis just means inflammation. So diverticulitis, inflammation of the diverticula, versus diverticulosis, it's just many little diverticula. Sorry. Thanks, Lyle. Appendix, when it gets inflamed, appendicitis, colon when it gets inflamed, colitis. So you can just recognize that as where the Latin root comes from. And when you hear itis, just note it's inflamed.

colorectal cancer

early detection

screening

lower gastrointestinal bleeding

diverticulitis