Great, so here we go. Colorectal cancer, lower GI bleeding, diverticulosis, and touching on hemorrhoids as well. So first, to talk about colorectal cancer, which is important to talk about because this is the second biggest cancer killer in the United States, about 100,000 of these a year in this country alone, and about half that many deaths related to this disease. It's number three for women. So a big epidemiologic burden in our country and in many countries across the globe. We call this colorectal cancer because it can occur anywhere in the colon, including the rectum, which is a part of the colon, and the lifetime risk on top of the statistics I just gave you is about 5%, so really hardly negligible. I showed you this graphic before in my earlier talk. Most colon cancers arise initially as precancerous polyps or adenomas, which go through an adenoma to carcinoma sequence that you see before you. And since we talked about that before, I won't reiterate it. But the real success story here is that by nipping them in the bud and getting these things while they're adenomas, or when they at most have a completely contained cancer within the mucosal layer alone, we can stop that progression with colonoscopy. Now patients can present without symptoms, so asymptomatic, they can present with suspicious symptoms or signs, or at worst, emergently with a bowel obstruction or a perforation causing inflammation of the abdominal cavity, which is called peritonitis, and those can be surgical emergencies. Nowadays we screen people earlier because the data supports that, so in normal risk individuals we start with first colon cancer screening at the age of 45, five years earlier in patients with a family history, and earlier still sometimes in patients with inherited colon familial colorectal cancer syndromes or with inflammatory bowel disease. However, screening is for asymptomatic individuals, whether normal or high-risk. Surveillance is for people who have proven disease to keep an eye on things. Screening tests are manifold. Colonoscopy is not the only one, although it's the best one in many ways. The old GWIAC-based fecal occult blood test, the GWIAC test, has been largely supplanted by something more sensitive and specific called the FIT test or fecal immunochemical test, where you test stool for the globin fraction of hemoglobin, but it's still looking for evidence of blood loss, which is presumed to be from polyps or colorectal cancer until demonstrated otherwise by a colonoscopy. There's a multi-targeted stool DNA test, which tests stool for DNA that can be seen and shed malignant cells or pre-malignant cells combined with looking for blood. This is what you know of commercially as Cologuard. There's flexible sigmoidoscopy, which reliably only sees the left side of the colon, typically at most, up to the distal transverse colon, so it misses most of the transverse, all of the ascending and the cecum in normal anatomy. Colonoscopy, which sees the entire organ and also has the advantage of being able to take biopsies and remove polyps, all in the same procedure as the screening or surveillance exam itself, and rarely undertaken as CT or MR colography or colonography, where CT or MR technology is used to provide even a fly-through type 3D exam of the colon, but again, rarely done, not very available, and rarely paid for by insurance. In diagnosing colon cancer, here are some pictures that are seen with colonoscopy, very, very graphic, and I probably don't even need to point out to you where the tumors are. In advanced stages, there can be frank ulceration or even perforation, resulting in peritonitis. So by performing screening colonoscopy and performing polyps before they go bad, we can prevent this sort of thing very, very easily. If the tumor's localized and is, frankly, cancer, then that can be cured via surgical resection. You can see that if there's a colon cancer here in the sigmoid, the sigmoid can be surgically excised and then these two free ends brought back together, and that junction is thereafter called the anastomosis. However, unfortunately, if the tumor has metastasized or spread beyond the colon itself to other parts of the body, that's rarely curable, and so the treatment is palliative to either reduce or slow down progression via chemotherapy and towards the end, palliative care for comfort. Moving on to lower gastrointestinal bleeding, this most commonly originates downstream from the ligament of trite, so downstream from the duodenum, so jejunum, ileum, colon. You can see blood emanating from the anus in an upper GI bleed, and that's the case about 10% of the time. The small intestine is not, as you can see, a common source of lower GI bleeding. The majority of it emanates from the colon. Bleeding can either be red blood or maroon blood passed from the rectum, or frankly, if that is chemically converted to hematin, you get these black, tarry stools, which are called melana. Sometimes you can get both. There might be a brisk GI bleed from the upper GI tract that is traversing the GI tract so quickly that it comes out red from the bottom to be followed by melana later on by the blood that traverses the GI tract more slowly. So if you see red blood per rectum, and that's coming from an upper GI tract source, then that's a very brisk bleed, and we'll talk about that more in a moment. There may be symptoms of anemia because you have blood loss, particularly if rapid, and there's volume loss, not enough blood or volume in the pipe, so to speak. There may not be enough blood being pumped to the brain, which can cause lightheadedness or even loss of consciousness, which we call syncope. If there is not enough getting to the heart, then that can give chest pain or shortness of breath, particularly on exerting oneself. So those can be the symptoms of anemia, particularly if severe or if that anemia is uncompensated. GI bleeding loss can come from a number of different causes or etiologies, as we say, in medicine. They may be anatomic, such as the presence of diverticula. Vessels that perforate into these can bleed, resulting in a diverticular bleed. There may be various vascular sources of bleeding. We talked earlier about angio-dysplasias or angio-ectasias, almost like spider veins at the mucosal level that can lose blood. There may be ischemia to the gut. You saw the purple small intestine earlier. And as that tissue starts to disintegrate, you can have oozing blood loss. And then there is also the potential for hemorrhoids, particularly internal hemorrhoids bleeding. With colon cancer, Frank cancer, or sometimes even larger polyps, one can see blood loss from that, and also from inflammatory bowel disease, be that, Frank, IBD, or from infection of the colon, resulting in blood loss, as Dr. Kossum talked about IBD just a few minutes ago. We can actually, as physicians or endoscopists, cause bleeding when we do a polypectomy. Sometimes there is a vessel in that area. And as the area that we burn undergoes ischemic degradation, that may lead to that tissue degradation right into an adjacent vessel, or a vessel that was formerly going through the stock of a polyp. And that can open up and bleed later on. When we deal with a GI bleed, we're mostly concerned about making sure that we immediately replace the volume that's been lost, because we don't want empty pipes to lead to some of the complications that I mentioned earlier, such as chest pain, shortness of breath, or even a heart attack or a stroke. To prevent that, the first thing that we do is introduce volume. We can worry about adding red blood cells to that volume later if that's necessary. We usually put in a couple of large-bore IVs, typically two, not only so that we can get a lot more fluid in quickly, but also if one fails, then you've still got another one to rely on. And we can typically give normal saline to just replace the lost volume to keep the pipes full so that the heart's pumping enough blood and fluid to the entire body to sustain life and prevent complications. And then when we check the hemoglobin level later on, if that's been diluted out too much, then we can always add units of packed red blood cells as needed. After we've stabilized the patient, then we think about endoscopy. And if we're worried at all about an upper GI source, a brisk upper GI source in particular, even though the blood is coming out the bottom, we may proceed even first with an upper GI endoscopy to see if we're dealing with, say, a peptic ulcer that's eroded into a blood vessel that's causing arterial bleeding. We will typically prep the colon, but sometimes if we feel like it's too urgent to undertake a prep to clean the colon out, we may go in and do an unprepped colonoscopy. But frequently, with a lower GI bleed, the degree of voluminousness of the bleeding is lower than with an upper GI bleed. So we can typically take our time and do a better job by quickly prepping the patient first and then going into a clean colon, identifying the bleeding source, whether that's a post-polypectomy site that's bleeding or, for example, a diverticulum. In those situations, frequently just using a small metal hemostatic clip will stop the bleeding. We may also inject with saline and or epinephrine to create tamponade or pressure, as we talked about earlier, to reduce bleeding or to even treat it. We may apply heat or electricity in the form of argon plasma coagulation or a bipolar coagulation probe to either obliterate small vessels, we'll burn them and they don't exist anymore, so then they stop bleeding because they're no longer there, or if it's a vascular source that's larger, we may compress the vessel with a heat probe and seal the front of the vessel to the back of the vessel and make it stop bleeding. Diverticulosis is a condition where there's a weakness in the muscle layer of the wall of the colon and the inner lining layer, the mucosa, can pooch through that weak area and cause these pockets or outpouchings of mucosa. We don't know exactly what causes these things, probably due to a combination of diet, heredity, age, et cetera. In most individuals who have these things, and many people have them, they're very, very common, and in most individuals who have them, they never develop any symptoms whatsoever, but sometimes they do. Of note, most of them occur in the sigmoid colon and sometimes also in the right colon, and this is what they look like in an endoscopic image, and here is a barium enema. You can see these little outpouchings probably in the sigmoid colon here. These can become inflamed and infected, in which case we call this diverticulitis, or as I mentioned earlier, they can bleed from a vessel in that area. If they become inflamed, that's called diverticulitis, and this can occur in up to 15% of patients who have diverticula. That means 85% or more never develop this. This usually presents with pain, and when it's in the sigmoid colon, it's typically left lower quadrant pain, and as it becomes more severe, it can result in a fever, which can be from inflammation or, frankly, from infection. If that inflammation becomes systemic, then that may raise the white blood cell count in the blood, which can be a clue, and as you can see, a CT scan can quickly diagnose this by demonstrating inflammatory signs around the area of inflammation or infection or both. If it's uncomplicated, we simply treat that with antibiotics. If it's complicated by an abscess or fistula formation, perforation, or at worst, and very rarely, a bowel obstruction, this may require decompression with an external catheter placement and interventional radiology or even surgery, and to prevent this from occurring again in individuals who have these complications recurrently, there may be elective surgery down the road to take that segment of the colon out to prevent this from happening again, and we sometimes send the patient for a surgeon to have an area resected if bleeding has recurred as well. Most diverticular bleeding, as we talked about, is the result of an artery in that area bleeding into the diverticulum. We can typically treat that with a clip endoscopically. However, the bleeding is usually mild and self-limited, and frankly, by the time we prep a patient and go in there, many times the bleeding has already stopped on its own. But if not, or to prevent future bleeding from that site, we could place a clip. Sometimes we'll send the patient to interventional radiology, where they will obtain access to the vasculature of the patient and treat the bleeding through methods such as injecting substances or coils into blood vessels that are feeding the source of bleeding. And I mentioned earlier, surgical resection and re-anastomosis can be a treatment or lead to prevention of recurrence. And then finally, hemorrhoids can cause inconvenience or more for patients. These are swollen veins, and they can be internal or external. The causes are protean. They include advanced age, pregnancy, pelvic tumors, prolonged sitting, such as truck drivers is an example that's frequently given, straining at defecation, particularly in patients with chronic constipation. What a picture that is. So I had to look at that one a few times. It looks awful. Anyway, in diagnosing simply a rectal examination, a careful one can determine if there are external hemorrhoids. Looking internally typically requires a short anus scope and colonoscopy, particularly with retroflexion in the rectum will reveal the internal ones. Many of these go away quickly with conservative management, softening the stool, sits baths where you just sit in a shallow bath. It's soothing to use warm water. Sit in a warm water bath relaxes the anal sphincter, which then allows better blood circulation in the area and promote healing. However, for internal hemorrhoids, band ligation with simple devices or with colonoscope can tackle that. Some also inject these with a sclerosant, and finally surgery can be done, rather simple to eliminate these. Thank you very much. I'm the only thing standing between you and lunch. Questions? No questions? Not quite. This is lunch. Not quite the almost.

colorectal health

colorectal cancer

lower gastrointestinal bleeding

diverticulosis

hemorrhoids