GI Case: 33-year-old Man with a 10-week History of Diarrhea

00:00 Let's move to our next case.

00:03 A 33 year old man is seen in clinic for a 10-week history of diarrhea and worsening abdominal crampy pain.

00:10 He has 6 to 8 bowel movements a day, including a few at night.

00:14 His stools are loose with streaks of blood and he has poor appetite and nausea but no fever.

00:20 He does not take any medications.

00:23 On exam, he is afebrile with a heart rate of 100 and blood pressure of 95/50.

00:30 His abdomen is soft with moderate diffuse tenderness in the lower quadrants with no rebound or guarding.

00:37 Colonoscopy shows patchy colitis with deep ulcers in a cobblestoning appearance and there is no involvement of the rectum.

00:46 So, what is the most likely diagnosis here? Let's look at some clues in this case.

00:52 So he has chronic diarrhea.

00:56 The presence of blood in the stools indicates that he may have an inflammatory diarrhea.

01:01 On his physical exam, he is tachycardic and mildly hypotensive which indicates probably, signs of mild hypovolemia.

01:09 And there is some keywords on his colonoscopy report such as cobblestoning and rectal sparing.

01:17 So, we put this altogether, he has chronic, bloody diarrhea which should automatically raise your suspicion for an Inflammatory Bowel Disease.

01:26 In addition, his colonoscopy report with patchy colitis and cobblestoning with rectal sparing should prompt you to think about Crohn's disease.

01:36 So, let's talk a bit more about IBD.

01:40 There are 2 types of IBD, they are Crohn's disease and ulcerative colitis.

01:45 They have very common clinical features and that they can both present with hematochezia, abdominal pain and fever, weight loss, a sense of fecal urgency or tenesmus.

01:57 They can both also present with symptoms outside of the GI tract.

02:02 So things like jaundice, uveitis, arthritis and lesions on the skin.

02:09 For the diagnosis, you first want to rule out any infection that could be contributing to their symptoms.

02:15 So, you would check a stool culture, a C. difficile toxin and a stool ova and parasites.

02:22 You may next also look for signs of inflammation in the stool.

02:26 So, a C-reactive protein or CRP and an elevated sedimentation rate or ESR can be helpful to look for systemic inflammation.

02:35 A fecal calprotectin can also be helpful because this is an inflammatory marker inside the stool that can help you track progression of the disease.

02:45 Lastly, you may do a colonoscopy to look for the specific features of each disease.

02:51 The treatment depends on the type.

02:54 So let's go into specifically Crohn's disease.

02:58 Crohn's disease is a transmural inflammation that can affect really any part of the GI tract.

03:04 So, the symptoms or clinical features you may encounter are diarrhea, abdominal pain, basically any symptoms involving the intestine.

03:13 You may have rectal bleeding, in the stomach, they may have vomiting, and it can also affect the liver and bile duct leading to inflammation.

03:22 Outside of the GI tract, patients may have inflammation or uveitis of the eyes.

03:29 They may develop skin ulcers and sores, One typical rash that we see often is erythema nodosum.

03:36 They may also have systemic signs of fever, weight loss and anorexia or decreased appetite.

03:42 They may also have ulcers in the mouth.

03:46 These patients tend to have frequent flares and remissions of their disease.

03:50 And because of the transmural inflammation, so that's inflammation extending through the wall of the bowel, there are common complications such as fistulae and bowel obstructions.

04:03 Treatment is done with corticosteroids for flares and for maintenance therapy, we give immunomodulators such as methotrexate or more advanced biologic agents that target the anti-TNF pathway such as infliximab.

04:21 Most patients, because of their relapsing and remitting disease will eventually require surgery.

04:28 Now let's talk about ulcerative colitis.

04:31 So, unlike Crohn's disease which is a patchy inflammation involving any part of the GI tract shown here, ulcerative colitis is a continuous inflammation that involves the colon and the rectum as shown here.

04:47 It usually does not involve the small bowel and it is associated with diagnoses like primary sclerosing cholangitis, cholangiocarcinoma and higher rates of colorectal cancer.

05:01 The treatment as with Crohn's is with first, corticosteroids for flares.

05:07 For maintenance therapy, we also give 5-aminosalicylic agents like mesalamine.

05:13 and we also have immunomodulators and biologics for severe disease.

05:17 So you might be thinking at this point that a Crohn's disease and ulcerative colitis have a lot in common.

05:23 So how do we tell them apart clinically? These are some clues that can help you make the diagnosis.

05:29 So Crohn's disease, again involves inflammation of the entire bowel wall, so transmural inflammation.

05:37 Also, patients tend to have skip lesions, so patchy involvement and a cobblestoning appearance.

05:45 They often have spared areas on colonoscopy.

05:48 On the other hand, ulcerative colitis involves inflammation limited to the mucosa and the submucosa only.

05:56 and inflammation tends to be continuous, so there are no skip lesions.

06:03 The location also differs.

06:04 With Crohn's disease, this can involve any part of the GI tract.

06:08 It typically, however, spares the rectum.

06:11 And the terminal ileum is the most common site.

06:14 With ulcerative colitis, only the rectum and the colon are involved.

06:20 The last thing to distinguish between the two are the common complications.

06:25 So if you remember that Crohn's disease involves transmural inflammation then you'll remember that fistulae and abscesses are more common with this disease.

06:35 With ulcerative colitis, associated complications are a higher risk of colorectal cancer and the association with the diagnosis of primary sclerosing cholangitis.