Now we move on to large intestine, we are going to talk about colorectal cancer, lower GI bleeding and diverticulosis, so I'll go through some of these conditions that we observe in colon or colorectum. Colorectal cancer, it's the cancer located in colon or rectum, it's actually one of the most common cancers, in fact excluding the skin cancers, 2023 colorectal cancer is the third most commonest cancer in US, used to be fourth, unfortunately we have now moved up, it's not good but you know it is the third most. And can you all guess where in US you have the highest rate of colorectal cancer? Any guesses here? It's actually lower Mississippi River Delta region, okay? You can guess based on the health and other conditions but it's the very very high rate over there. Lifetime risk, it says 5%, so 1 in 23 in male and 1 in 26 in female, it's a good number to know, 1 in 23, 1 in 26. Okay so the natural history, as you know most of these colorectal cancers that we observe they start off from polyps, now what are these? So you see these initially start developing proliferation or we call it hyperproliferation of the colonic or colorectal epithelium, then they start developing these small projections, we call them polyps. Now the word here is adenomatous polyps, the hyperplastic is another type of polyp we normally see mostly in the rectum and also in the left colon sometimes that are not related to the progression to cancer by the way, okay? So when we call adenoma that's by definition has some changes on the lining, meaning the mucosa of the colon or rectum and those adenomatous polyps obviously increase in size and then they start developing as I was mentioning high grade dysplasia, so that's in situ cancer basically. We don't use the word, we basically use the word dysplasia, high grade. Adenoma by definition obviously has low grade. So this is the high grade dysplasia which is a worrisome feature because these things if left behind will develop into full-blown adenocarcinoma which can either be just located in the lining and the mucosa or then now you start seeing the invasion through the submucosa. So clinical presentation mostly asymptomatic by the way, sometimes you can have some suspicious symptoms and signs, mostly anemia and then emergently sometimes you see these people present with either obstructive symptoms or peritonitis which is the inflammation of peritonium because of the perforation. So because they're mostly asymptomatic, at least in the diagnosis part, what do we do? We need to really start instituting screening for identifying these high risk lesions, especially adenomatous polyps. Now 45 is our new 50, used to be 50 years old when we start screening for colorectal cancer, we just now changed to 45. There are other few indications for screening and again, family history of colorectal cancer. So these are called, we call it high risk screening individuals. If you have inherited colorectal cancer syndrome, namely familial adenomatous polyps for example, FAP in short and then inflammatory bowel disease which you'll hear from Dr. Abram later on. So these are some of the conditions where obviously we start screening and some of them we start actually earlier than before, especially for the fact that if you have a family history of colon cancer and the person developed that cancer before say, you know, at the age of 50, you then start screening at the age of 40, not 45, okay, just want to make it clear. So what are the screening modalities? Obviously we have gone through quite a few, we used to do the fecal-occal blood test, then came the GUAC-based fecal-occal blood test which we don't do it that often nowadays, we do mostly FIT in short or fecal immunochemical test is the immunoantibodies against the global part of the hemoglobin, okay, the globin part is where we detect this blood in the stool. You probably heard a lot about this multi-targeted stool DNA test, in short ColoGuard, you know, it's on the TV all the time, it's a good test for people who don't want to undergo the definitive procedure called colonoscopy. Now colonoscopy, and then you also have flexible sigmoidoscopy and CT colonography which is a radiologic exam, these are all the different screening modalities, but this colonoscopy is the only one, I repeat again, the only one which is a preventive exam, so it prevents progression of those adenomatous polyps you saw into cancer. So this is sometimes we see, unfortunately, which we should not be seeing, but we do see a variety of these colon cancers, either presenting sometimes with anemia, obstructive symptoms, or occasionally with hematokizia, or sometimes even melina, or black stool. So the treatment obviously depends on the location of the tumor, and if they have obstructive symptoms, obviously we proceed mostly with surgical resections, again depending on the stage. These are the times where we really sit down with our surgical oncology and medical oncology colleagues and then make a joint decision. But most of the time, as you see, if you have a tumor in the sigmoid colon, then we actually do a resection, it's called a Hartman's procedure, and then they do this anastomosis, and after that a patient goes for medical oncology consultation, if needed. If tumor is metastatic, obviously it will be a medical oncology consultation where they will institute chemotherapy, but if the patient is too sick, the poor performance status we call it, PFS, then they undergo palliative care. We do have a very good palliative medicine department where they help us with these patients. Lower GI bleed, that's another common thing we see, as we were mentioning, it's beyond any bleeding that happens or originating beyond the ligament of trites. Now ligament of trites is where, as I was mentioning, when you start seeing these duodenum, they go and start, you know, the proximal duodenum, that curve, that's a ligament. That's where the ligament of trites happens, from the proximal jejunum onwards, anything, any bleeding. Hematokizia mellina, we already talked about. Symptomatic anemia, sometimes we do see people coming in, often with, say, occasional blood in the stool noted at home, but they're present with lightheadedness, sometimes presyncope or syncope, shortness of breath, or chest pain. So these are the various conditions that can give rise to hematokizia mellina or anemia or symptomatic anemia. You see these pockets in the lining of the colon, these are called diverticula, and the presence of diverticula in the colon is called diverticulosis. Now these pockets, or these pits, you can get either infected, you'll see often stool sitting there, we call it ficolates, lodged in these pockets, and then they occasionally bleed too. We talked about these abnormal vessels, these are, they call it angio-dysplasia, it's not a cancer or anything, it's just an abnormal-looking vessel, it's angioectasia is another right word. We do see ischemic colitis, you can see these changes in the lining of the colon, you can see more pale appearance, sometimes they bleed too. Now you heard from Dr. Mathur earlier that these happen in those areas where there is a less blood flow, so these are called the so-called watershed areas in the colon. If you recall the anatomy, these are mostly in the hepatic flexures, mostly where there are curves. So hepatic flexure, splenic flexure, and then sigmoid flexure, the recto-sigmoid, these are the common areas where we see these ischemic appearance, and because of those, we call it these marginal vessels, or the marginal arteries, which often get broken down or clogged, and that's why you develop this condition. That's another condition where you'll see red blood per rectum, most of the time they'll be telling you that, Doc, after wiping the rectum, we see blood streaks on the tissue paper, so that's more like hemorrhoidal bleeding. This is the malignancy, we just saw that, different conditions, Dr. Abram is going to talk about most of, you know, this condition is called inflammatory bowel disease, where you can see these flurry changes in the colonic lining of the epithelium, and it can be either ulcerative colitis or Crohn's colitis or Crohn's disease. We do see quite a bit nowadays, this kind of condition is called infectious colitis, and in this case it's mostly pseudomembranes, and this is commonly caused due to infection with Clostridioides difficile, C. diff in short, from antibiotic usage and other conditions. This happens not that often, but we do, after removing a polyp, you may have a vessel in the base and that can bleed when you start patients on either certain blood thinners or antiplatelet agents or even aspirin. For management, what do you do? Again, the basic ABCs, you start with the two large board IVs, volume resuscitations, often give blood as needed. You obviously exclude the upper GI, so always, always, as I said, 12 to 15% of the time you can have an upper GI source, you put a nasogastric tube, make sure you do a good lavage, make sure there's no upper GI source. Often we do the colonoscopy, as I'll come to that, and if you don't find any obvious cause, we go and do immediately the upper endoscopy too, so we consent for both all the time for patients presenting with hematokinesia. So what are the different modalities? We do use these clips, as you can see, sometimes even post-polypectomy, we can put clips just to prevent any further bleeding. This is the bleeding I was mentioning happening from those pockets in the colon called diverticula, and it can be sometimes challenging to control these, so we try different types of clips to close those defects, and after doing a local epinephrine injections. So this is the epinephrine injection I was talking about, we do one in 10,000, you know, using the scleroneedle, we inject around the area that's bleeding from. The goal is here with the epinephrine, you're cutting off, you're shutting down any vascular supply to the bleeding lesion, okay? So that's the goal, and then you can use for hemorrhoidal bleeding, these bands, I'll come to that later, I think there's a picture there in the end, different types of modalities to treat the hemorrhoids. Now for the angioectasias, we use argon plasma coagulation, I think, again, you heard from Dr. Kumar earlier that this is basically shooting plasma, which is an ionized form of argon gas here, in this case, it's inert material, and then using that, we convert into this thermal coagulation, it's very superficial, but another advantage of argon plasma coagulation, it actually, the coagulative effect spreads laterally, so you can pretty much get a wider area coagulated with this approach. We do have another modality other than argon plasma, now we use a radiofrequency ablation or RFA probe through the instrument channel in our colonoscope to treat this condition called radiation proctopathy, because we see sometimes abnormal vessels, you can see these kind of very tortuous vessels that develop post-radiation, mostly for prostate cancer in males. So diverticulosis, we mentioned outpouching, so these pockets in the lining of the colonic mucosa, submucosa, increased incidence with age, usually asymptomatic, mostly in the left versus the right side, and these are these outpouchings we are talking about, but when you are doing the colonoscopy, it looks like these pockets in the colon, as you saw that, and this is a classic old barium enema, you can see these nice outpouches. Can get infected, that's a condition called diverticulitis, now it's not just the presence of diverticula, which is called diverticulosis, now they get infected, it's itis, and you can get bleeding. Now it affects 4-15% of patients with diverticulosis, it's inflammation or infection of diverticulum, not all the time it's infection, to be honest with you, you can now, we know, you can just have an inflammation from a variety of other conditions, which can give rise to this condition. Usually what you develop is symptoms, left-sided abdominal pain, fever, elevated white count, but as I mentioned, it's not always it's infection. This is where the CT scan, you can see this, you know, increased edema of the wall of the lining of the sigmoid colon, in this case it's sigmoid colon. So most of the time, the treatment for an uncomplicated diverticulitis will be a short course of antibiotics, although again now, latest guidelines, like we can just observe and we don't have to always use antibiotics. Only in the complicated cases of diverticulitis, where patients get admitted in the hospital through the emergency room, you start on IV antibiotics, and you look for these conditions, either you develop abscess, fistula, perforation, or bowel obstruction. Sometimes we manage mostly conservatively with bowel rest, IV fluids, IV antibiotics. Often we get the IR, interventional radiology consult, just to see if the abscess needs to be trained. Rarely these patients go for surgery though, nowadays, if you catch them early. The bleeding happens from these vessels, which are eroding into the base, as I was mentioning. So this is what the lumen of the sigmoid colon looks like, and you can see these pouches, these are the diverticula, and these are the vessels, and these vessels actually, they penetrate and they go into the pit of these, and the bleeding actually happens mostly from this edge, where these perforating vessels go into the pit. Majority of the time, I mean, so they're present as painless rectal bleeding, and these are self-limiting, by the way. I know people really get a little nervous seeing a lot of blood in the stool, but to be honest with you, lower GI bleed has less morbidity mortality than the upper GI. In fact, it's less than 2%, whereas the upper GI can go as high as 5% to 7%. So lower GI bleed is not as bad, however, you know, in certain cases we do see significant bleeding, where we either have to do urgent colonoscopy. Now when I say urgent, we don't have to do it right away, we do bowel prep or bowel purging, and then we do mostly within the next 12 to 14 hours, and try to control it with a variety of modalities. You saw some of the tools earlier. And then the other option we also use is the interventional radiology doing an NGO. Sometimes we do a CT NGO first to localize, and then interventional radiologist goes and then embolize these feeding vessels to those diverticula. Either they are coming from the superior mesenteric artery or inferior mesenteric artery, so we do selective angiogram and do the embolization and stabilize the patient. Rarely again, patient have to go for surgery for these conditions. Finally we are coming down to the rectum, and this is what you see, you know, these hemorrhoids, the internal hemorrhoids above the dented line. So here is the dented line, which is separating your rectum from the inner canal, okay? Now these are basically nothing other than venous cutions, which are basically swollen from straining or constipation, and it can be either internal or when they are more distal to the dented line, they become external hemorrhoids. In this case, you see some of these external hemorrhoids are even protruding out of the inner verge, and you can even palpate or feel it. Now happens with advanced age, pregnancy, pelvic tumors, prolonged sitting, straining and chronic constipation. See this is the key here, and the longer you sit on the toilet, the higher chance that you have hemorrhoidal conditions. In fact, you know, there have been studies showing that more than five minutes will definitely increase the cause of internal hemorrhoids. So how you diagnose? Most of the time we are diagnosing during colonoscopy, when we do the last part of the exam called retroflexion, or sometimes even an anti-grid view. Doctors love to use the endoscopies, and also by digital rectal exams we can identify these hemorrhoids. If we are planning to do any therapies in the office, sometimes we definitely use endoscopes. So most of the time the management is conservative, medical management, avoiding straining, constipation very important, increasing fiber in the diet, drink a lot of water. And then you use topical steroids and suppositories, mostly steroid-based suppositories. And sitz bath, very, very important. It really helps. You can just put some Epsom salt in warm water, and then just before showers you can sit on it. It really helps to shrink these hemorrhoids. Procedures we do, these are the ones I was talking about, we do these rubber band ligation techniques. There are special systems available, a CRH Oregon system is one of them. We don't do any more scleros, nowadays we do mostly either cryotherapy for these hemorrhoids. It's mostly done by the colorectal surgeons. The definitive approach, obviously, is the surgery, the hemorrhoidectomy, where they identify the column and go and actually resect those out. Having said that, the recurrence rate happens, even after hemorrhoidectomy, because a lot of times we get people asking, oh, doc, I'm still having issues after that. Yes, this is not 100%, so 10 to 20%, depending on the type of columns that has been taken care of before by surgeons, you can develop recurrence. Any questions?

large intestine

colorectal cancer

lower GI bleeding

diverticulosis

hemorrhoids

screening modalities