Approach to hematochezia: Clinical sciences

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Introduction0:00–0:33

Hematochezia refers to the passage of bright red blood or blood clots from the rectum. It is seen in patients with acute lower gastrointestinal bleeding that originates from a site distal to the Ligament of Treitz.
Hematochezia might also occur in massive upper gastrointestinal bleeds. When bleeding comes from the right side of the colon patients usually pass dark or maroon-colored stool while those with bleeding from the left side pass bright red blood or stool.The first thing to do when assessing a patient with hematochezia is the ABCDE assessment to determine if your patient is unstable or stable.

Unstable patients0:33–2:01

If the patient is unstable, begin acute management by stabilizing the airway, breathing, and circulation. Next, obtain IV access and initiate IV fluids for immediate resuscitation.
If your patient is actively hemorrhaging, you may need to transfuse your patient with blood products as well. Finally, start continuous vital sign monitoring, including pulse oximetry, blood pressure, and heart rate.Once acute management is initiated, the next step is to obtain a focused history and physical exam, and order labs, such as blood type and crossmatch, CBC to monitor hemoglobin and hematocrit, coagulation studies, and CMP.
Your patient may present with massive hemorrhage or have brisk bleeding. You should be on the lookout for signs of hemodynamic instability including hypotension and tachycardia.
At times, the bleeding may cease, but you should always monitor for rapid rebleeding. Initial labs may show low hemoglobin and a normal blood urea nitrogen-to-creatinine ratio for a lower gi bleed.
However, if the ratio is elevated, consider upper gastrointestinal bleeding.Alright, now that history, physical, and labs are obtained, let’s move on to nasogastric lavage.

Upper endoscopy/Nasogastric lavage2:01–3:03

Nasogastric lavage is performed by placing a nasogastric tube and instilling water or normal saline into the stomach. The liquid is then aspirated.
If blood returns you have confirmed an upper gastrointestinal or GI bleed. On the other hand, if there is no blood, a lower GI bleed is more likely, so you’ll need to identify the source.
If this is the case, the next step involves a tagged RBC bleeding scan and angiography, as well as controlling the bleeding with interventional radiology embolization, endoscopic intervention, or in extreme situations emergent surgical intervention or resection.
These procedures are both therapeutic and diagnostic, so besides treating the bleeding, you will be able to find the source and confirm your diagnosis of lower gi bleed.
Now that unstable patients are taken care of, let’s talk about stable patients. Your first step here is to obtain a focused history and physical exam, including a digital rectal exam, as well as labs like CBC for serial monitoring of hemoglobin and hematocrit, coagulation studies to assess the need to correct a coagulopathy, and blood type and crossmatch.

Stable patients3:03–3:40

In addition, you may want to order an abdominal and pelvic CT scan with oral contrast to look for pathologies that can cause GI bleed.
Another important factor is to assess for rectal pain. So, let’s first talk about cases where there is no rectal pain associated with the bleeding.Causes of painless hematochezia include colorectal cancer, Dieulafoy lesion, diverticular bleeding, and angiodysplasia.Let's start with colon cancer.

Colorectal cancer3:40–4:42

These patients typically report a low-grade, mild, or recurrent bleeding, as well as unintentional weight loss. CT scan typically shows a mass that protrudes from the colonic wall and narrows the lumen.
In this case, you should consider a neoplasm of the lower gi tract, in either the colon or rectum and the patient should be set up for a colonoscopy with a biopsy.
Findings might include overlying erosion or ulceration with a friable mass and low-grade bleeding. If biopsy results confirm cancer this is your diagnosis.Alright, let’s move on to the Dieulafoy lesion.

Dieulafoy lesion4:42–5:31

A patient may present with bleeding that can be self-limited but might recur and at times be profuse. History might also reveal some important risk factors like biologically male sex, cardiovascular disease, diabetes mellitus, hypertension, kidney disease, or alcohol use disorder.
In this case, you should consider a Dieulafoy lesion and order a colonoscopy. Findings usually include a dilated aberrant submucosal vessel eroding the overlying epithelium without a primary ulcer, as well as mucosal atrophy or arterial spurting.
If you see these, the diagnosis of the Dieulafoy lesion is confirmed.Let’s switch gears and talk about diverticular bleeding.

Diverticular bleeding5:31–6:45

Diverticulosis refers to the presence of multiple diverticula in the colon. This is often asymptomatic or may present with painless bleeding, which can be massive and even life-threatening.
Now, CT scan can support the diagnosis of diverticulosis by revealing multiple diverticula arising from the colonic wall.
In this case, you should order a colonoscopy. If you see a penetrating vessel within the bowel lumen, diverticula with arterial vascular penetration, and active arterial bleeding, you can confirm the diagnosis of diverticular bleeding from diverticulosis.
Here’s a high yield fact! People with diverticulosis can also develop diverticulitis, where the diverticula become inflamed and painful.
What’s important to keep in mind is that, although colonoscopy is the most accurate test for definitive diagnosis of diverticulosis, it must be avoided in patients with diverticulitis because there’s a high risk for perforation!Okay, the last cause of hematochezia without rectal pain is angiodysplasia.

Angiodysplasia6:45–7:28

History typically reveals severe bleeding that is painless and can be episodic or self-limited. Sometimes, it can also be an occult bleed diagnosed on a fecal occult blood test.
In this case, you should consider angiodysplasia and again order a colonoscopy. On colonoscopy, these patients have dilated, tortuous submucosal vessels with peripherally expanding dilated capillaries with central origin.
The bleeding in this case is usually venous in origin. If you see these findings, the diagnosis is angiodysplasia.Alright, now that all causes of hematochezia without rectal pain are covered, let’s talk about a second set of stable patients that do present with rectal pain.Causes of painless hematochezia include infectious or inflammatory colitis, or IBD, anorectal causes, like hemorrhoids or anal fissures, and Radiation Telangiectasia or Proctitis.Some patients may report abdominal pain, fever, dehydration, and mild bleeding.

Rectal pain7:28–7:55

Infectious or Inflammatory Colitis or IBD7:55–8:32

If you see this, consider infectious or inflammatory colitis or inflammatory bowel disease. Next, order a colonoscopy to confirm the diagnosis.
Findings might include signs of bowel inflammation like edema, friability, erythema, ulceration with fibrin exudates, or crypt abscesses.
These would lead to the diagnosis of inflammatory conditions, such as infectious or inflammatory colitis, or inflammatory bowel disease.On history, some patients may report mild bleeding or blood-coated stool.

Anorectal causes and hemorrhoids8:32–9:22

They can report pruritus or an external mass that is unable to be reduced and is painful. In these patients, you should consider an anorectal cause of hematochezia.On physical exam, you may see a prolapsed internal hemorrhoid with or without an external lump that may be thrombosed.
You might also see skin tags which would indicate previous hemorrhoid issues. These patients should then undergo anoscopy for further workup.
Anoscopy typically shows dilated submucosal veins in the anus above or below the dentate line. This confirms your diagnosis of hemorrhoids.Okay, let’s go back to the physical exam.

Anal fissure9:22–9:52

On a physical exam, you might notice a fissure. Anal fissures are lacerations in the anoderm and are very tender to palpation.
They are typically located in the posterior midline, but they might sometimes be seen in the anterior midline. You might also see perianal skin tags which indicate a previous episode of inflammation or hemorrhoids.
If you notice any of these findings you can diagnose anal fissures.Alright, the final cause of hematochezia with rectal pain involves radiation telangiectasia or proctitis.

Radiation telangiectasia or proctitis9:52–10:45

These patients typically report mild bleeding, rectal urgency or tenesmus, and diarrhea. They also have a history of radiation therapy for abdominal or pelvic cancers.
Based on these findings, you should consider radiation telangiectasia or radiation proctitis. Your next step here is to order a colonoscopy.
Typical colonoscopy findings include epithelial damage to the rectum with minimal or no inflammation. They may have friable, edematous, and erythematous mucosa with telangiectasias and mild bleeding.
This confirms the diagnosis of radiation telangiectasia or radiation proctitis.Alright, as a quick recap… Patients with hematochezia might be unstable or stable.

Review10:45–12:05

Unstable patients often have massive bleeding and may be exsanguinating. You should first stabilize the patient and then identify the source of the bleeding.
Next, an upper GI bleed should be ruled out with a nasogastric tube lavage. Once upper GI bleeding is ruled out, you should proceed with tagged RBC bleeding scan and angiography, as well as controlling the bleeding with interventional radiology or surgery.
On the other hand, stable patients with signs and symptoms of gastrointestinal bleeding should be evaluated for the presence of rectal pain.
If there is no evidence of pain, they should be assessed with colonoscopy and sometimes biopsy. The potential diagnoses here include colorectal cancer, a Dieulafoy lesion, diverticular bleeding, or angiodysplasia.
On the flip side, if a patient has a history of rectal pain you should consider anorectal causes such as hemorrhoids which can be diagnosed on anoscopy, or fissures which are diagnosed on a physical exam.
Alternatively, in patients with a history of radiation therapy, a colonoscopy should be done to confirm the diagnosis of