So, I have three topics to cover, colon cancer, lower GI bleeding, and diverticulosis. Colon cancer is probably the second most common cause of cancer in men and women in the United States. Its lifetime risk has actually dropped on this slide from 5% to 4%, and that's due to our mass screening programs that aren't completely in use in a lot of places, but the more we use them, the more we've been able to make an impact on the incidence of new colorectal cancer as well as the mortality from it. I showed you this slide briefly earlier. This is the natural history of something going from a very small little bump, little bitty polyp as it grows over time. This is a 10 to 15 year process going from a tiny little polyp to a larger, larger, larger, and then invasive cancer. So, we're hoping to pick things up when they're in their early phases with screening procedures and remove them and prevent cancer. How do patients with colon cancer present? Well, unfortunately, many of them are asymptomatic until it's too late. They may have symptoms like change in bowel movements, thinning of the stools, passing blood mixed into the bowel movement, or they may present urgently with a very advanced cancer that causes an obstruction of the colon or perforates and causes peritonitis and requires emergent surgery. So, hence, we have developed screening programs, and screening has really made an impact, as I said earlier, on the incidence of colon cancer and the mortality. As you're probably aware, in the last few years, the age of recommended age for screening has dropped from age 50 to age 45. That's because we're seeing more and more young people with colon cancer, so it was determined that lowering the age to 45 would have an impact on new diagnosis and mortality. Other people who have a higher risk that may start getting their colonoscopies before age 45 are those who may have a family history of colon cancer and a younger person in the family, a first-degree relative, those who have inflammatory bowel disease, as we already heard, and those who have genetically inherited colorectal cancer syndromes like Lynch syndrome, multiple FAP, familial adenomatous polyposis, genetic things that can create a very high risk for colon cancer. So, that group of people may have colonoscopies for screening done at a much earlier age. This slide shows the available tests that are for colon cancer screening. The two that are probably most widely used are colonoscopy, which is the gold standard to which all of the rest of these are compared, or fecal immunohistochemical testing, which is a test for human blood in the stool. And then there's the stool-fit DNA test, which you've heard of, called COAGARD, which has had a big direct-to-consumer marketing push, so a lot of people are getting that as opposed to the less expensive fit test. So, just looking at these, colonoscopy, as I said, is the gold standard. So, it's one-stop shopping. You get sedated. You have the procedure. We find the polyp. We remove it. You're done. Or we find nothing, and you come back in 10 years if you're average risk. The downside is that it requires a prep. It requires sedation, therefore a day off work, and it's more costly. And it's riskier because we are sedating you and, you know, we're pushing stuff through your bowel, so there's always a risk of, very low risk of perforation, aspiration, things like that. And some people are very fearful of colonoscopy or are not very fit for a colonoscopy, and therefore, we may want to offer them a less invasive screening, which would be a stool test, such as the fit test, which is just that human blood test, costs about $35. If you choose to do that, you have to do it annually, and that's the downside, is a lot of people kind of get lost in the follow-up scheme, and they don't come back annually to have it done. If that test is positive, it's automatically recommended to have a colonoscopy. And the same way with the stool fit DNA test or the AKA Colgard, that test is only done every three years. It picks up human blood or genetic material DNA shed off of a tumor. When you get a positive fit, you really don't know which part is positive. You just have to go in and evaluate, and if the colonoscopy is negative, then you're done. That one, as I said, is every three years. It is quite a bit more expensive than fit testing, but it is non-invasive, so some people just simply prefer that for that reason. So this is what a colon cancer looks like endoscopically. It's just a big mass. This is mostly obstructing the lumen. The lumen's right there. You probably wouldn't be able to get a colonoscope through there. Same with this and this, and this is one we could get past. This looks like it's in the transverse colon, and it's just halfway around the lumen. Clearly, none of these can be removed endoscopically. There's nothing we can do here but take a biopsy and get out. So the treatment, if it is like one of these tumors, is surgery to resect the primary lesion, and the site of surgery obviously depends on where the tumor is. In this case, it's in the sigmoid colon, so they've removed the sigmoid, and we, the surgeons, do a primary anastomosis and sew this back together. These sorts of surgeries have become more and more less invasive. This is usually now done robotically. Patients may be in the hospital 24, 48 hours and go home, so that's a huge step forward in how we used to operate on these things. If the tumor's metastatic already, it's in the liver, it's in the lymph nodes, it's in the lung, then patients usually get chemotherapy, and if it's very advanced, maybe just palliative therapy. Moving on to GI bleeding. So lower GI bleeding basically means patients passing a lot of blood per rectum. For lower sources, a lot of times it's bright red blood, it might be burgundy-colored blood, and on occasion, if the blood is making a very slow transition through the colon, it may be black in color called melanin. Most of the time, lower GI bleeding is from the colon, about 85% of the time. About 5% of the time, it's from the small bowel. It's kind of more obscure bleeding. It's harder to find in the small bowel because we don't really have great tools to examine the whole small bowel except for video capsule, which is not something we can do urgently for a patient that's bleeding. 10% of the time, it may be in the upper GI tract. Hence, sometimes we will do an upper endoscopy to evaluate these people, even though it seems like they're presenting with lower GI bleeding. The symptoms are the word hematochesia, which means bright red blood per rectum, or melanin, which means black, tarry stools. Sometimes patients don't present with overt bleeding, but they present with just symptoms of anemia, so occult bleeding, slow, oozing. The blood is mixed into the stool and you can't see it because it's coming out so slowly, but you may detect it on a stool test for blood. These patients may just mainly have symptoms of the anemia alone, just lightheadedness, maybe dizziness, chest pain, or they may pass out when they get anemic enough. There are many, many causes of lower GI bleeding. They're all kind of pictured here. There's the anatomic bleeding, which is from diverticulosis. There's malignancy, of course. There's vascular causes of bleeding, like angiodysplasias. I mentioned those earlier. These are these superficial little blood vessels that can ooze, and that's the ones we use the blowtorch on, the argon plasma coagulator. You can have interruption of blood flow and ischemic colitis, which causes a lot of pain followed by dumping a lot of blood and diarrhea. You can have hemorrhoidal rectal outlet bleeding. We can have inflammatory conditions like IBD, infectious colitis, and then iatrogenic causes, like we've removed a polyp, and then it bleeds. Polypectomy sites can bleed for up to two weeks after the polyp is removed. So when we do a big polypectomy, we have to be very cautious with patients and ask them not to take NSAIDs or aspirin for two weeks to lower the likelihood of giving them fuel to the fire, if you will, to have a bleed from a site. And if they do bleed, then we have all the therapeutic interventions we talked about earlier. So when a patient comes in GI bleeding, real bleeding, they're usually very unstable, so they're hypotensive, they're in shock, they're clammy, their heart is racing. They may even, depending on how bad it is, may be a little disoriented or near syncopal. The first step is not endoscopy in that case, although endoscopy is going to be used to find what is bleeding. We need to stabilize the patient first, so we always put in big IVs and infuse normal saline, give blood if necessary, and get their volume resuscitated to where their pressure is stable enough that they can now undergo an endoscopic procedure. May need a blood transfusion, as I said. So management is usually endoscopic. We also may put a nasogastric tube down. Sometimes they come in, they've got this burgundy blood, and you're not really sure, is it lower, is it upper? And, you know, you hate to waste your time doing a colonoscopy if it's really an upper source, so we a lot of times will put in a nasogastric tube and lavage the stomach to see if we get blood back. If blood come back, then we know we need to start with an upper endoscopy. If we're uncertain and they're unstable, we might start with an upper endoscopy anyway just because that's a very easy thing to do, and if we find it, we're done. And if not, then we try our best to purge the colon out with a prep, rather semi-urgently, and then get in there with a colonoscope. And when we do find the bleeding source, a lot of times we don't, but if we do, then of course we have some endoscopic therapy we can do here with the post-polypectomy bleeding. You see us putting a clip on. Diverticular bleeding is probably one of the more common causes of lower GI bleeding that gets patients in the hospital. Unfortunately, patients who have diverticula tend to have hundreds of them or, you know, just all over the place, and once they've purged the colon of blood, you really can't always tell which one bled. So if you're lucky, you'll find a spot like we see here in this lower left picture that's a diverticulum there, and then you see the blood coming out of it. They've been able to inject some epinephrine, I think, here, because the tissue around it looks a little pale. So they've slowed it down. They can see it better, and now they're putting some clips on, on the artery in there to make the bleeding stop. We also, well, epinephrine injection is listed here as one of the treatments that we do. Epinephrine is just mainly used to slow bleeding or stop bleeding so we can get a better look at what the site is so we can target more definitive therapy. We sometimes will, here's a rubber banding. This is a hemorrhoid, actually, that's rubber banded. That's what it also looks like in the esophagus when you pop a rubber band on the tissue. The bleeding had been from the tip of this hemorrhoid, and now you've stopped it, strangulated it, and that's going to fall off in a few weeks. We have the argon plasma coagulator for those superficial lesions and for radiation proctitis that sometimes causes rectal bleeding. So moving on to diverticulosis, very, very common. Many people have it. Many people over the age of 50 find it on screening colonoscopy, and it's simply an outpouching of the lining of the colon to make little pockets, if you will, on the outside of the bowel wall. They're most commonly in the left colon, but more extensive cases can have it in the right as well. They're usually, as I said, asymptomatic. Patients sort of go, oh, I have diverticulitis. I'm like, no, you have diverticulosis, which are just pockets that exist in the bowel wall with aging. So for most people, they cause absolutely no problems, and they don't need to do anything differently. We say high fiber diet is good. We don't change their diet in any other way. Now oftentimes, like I said, they're found on colonoscopy. Sometimes we find them incidentally on imaging. We don't do very many barium enemas anymore, but we do a lot of CAT scans. So frequently, we'll see them on CAT scan. They can have two different types of complications, okay? One is infection. That is diverticulitis. That's what that term, the itis, means, infection or inflammation. Or they can bleed. So diverticulitis is in one of these little pockets, essentially sort of ruptures. It's like a micro-perforation, and the body responds by walling it off and sending white blood cells and inflammatory stuff around it to keep that from sending bacteria and tissue and such into the bloodstream. The symptoms that come with this are usually left lower abdominal pain. It's most often in the left side. Some patients may have fever, elevated white count. The diagnosis is not made with a scope. It's made with a CAT scan. You don't want to put a scope up there in something that's got a micro-perf because you may blow that open. So we'll usually do imaging. And the treatment for uncomplicated diverticulitis actually is now recommended is liquid diet for a couple of days, and very frequently, it will regress and the patients get better and they don't require antibiotics. If they don't, we'll usually use antibiotics to cover a broad spectrum of bacteria like a fluoroquinolone and metronidazole. If it's complicated, big perf, big abscess, bowel obstruction, then that patient may require surgery. Most of the time, fortunately, we can get them better without that. And then we have diverticular bleeding. This is where an artery erodes into the base of the diverticulum, and it can really hose. It can turn blood on like a faucet. Just blood can pour out, and then it usually most of the time just stops on its own. The pressure drops. The blood pressure drops enough. The perfusion drops. The bleeding stops. And they usually come in with painless bright red blood. The diagnosis is made by a colonoscopy usually. Sometimes if they're massively bleeding, we can't see well enough to find a bleeding spot and we'll do angiography, which is here, and you can see the bleeding spot is right there. It's leaking out into the lumen of the bowel through the arteriogram. Lastly, hemorrhoids, swollen veins. We talked about these before. I'm sure many people are familiar with these. They can hang out on the outside of the rectum. They can be up on the inside, and these here tend to cause painless bleeding. The outside ones may cause pain or may just cause bleeding and swelling. The causes are pressure, pressure in the rectum, prolonged sitting, straining at bowel movements, pregnancy, pelvic tumors. The diagnosis is usually made by rectal exam for the external ones. We can't see or generally feel internal hemorrhoids on just digital rectal exams, so that requires putting a little scope in the rectum, like a small anoscope, or more frequently refine them at colonoscopy, oftentimes just incidentally. The treatment is conservative, mainly. We try not to operate on them. Surgery for hemorrhoids can be very, very painful, so we tend to try to manage with measures such as avoiding straining, softening the stool, using topical steroids or suppositories when needed, sitz baths to reduce the swelling. And many people will get better with simply that. Occasionally, they'll need to move on to in-office procedures like rubber band ligation or sclerotherapy, and less commonly to out-and-out surgical hemorrhoidectomy. And that ends the talk. Ooh, I didn't do bad. Thank you.

colon cancer

lower GI bleeding

diverticulosis

mass screening programs

endoscopy