# Clinical Cases: Inflammatory Bowel Disease

## Case 1: Crohn's Disease

### Patient Presentation
**Demographics:** 24-year-old female

**Chief Complaint:** Chronic diarrhea, abdominal pain, and weight loss for 6 months

**History of Present Illness:** The patient reports 4-6 loose, non-bloody stools daily with crampy right lower quadrant abdominal pain that partially improves after bowel movements. She has lost 18 pounds over 6 months. She has developed a painful perianal lesion that is draining purulent material. She also reports joint pain in her knees and ankles and has noticed painful mouth sores.

**Past Medical History:** None

**Family History:** Uncle has "bowel disease" requiring multiple surgeries

**Social History:** Non-smoker, occasional alcohol

### Physical Examination
- **Vital Signs:** BP 108/68 mmHg, HR 92 bpm, Temperature 37.6C, BMI 19
- **General:** Thin, pale female appearing chronically ill
- **Oral:** Two aphthous ulcers on buccal mucosa
- **Abdomen:** Tender fullness in right lower quadrant, no peritoneal signs
- **Perianal:** Draining perianal fistula at 5 o'clock position
- **Musculoskeletal:** Bilateral knee effusions, tender ankles

### Workup and Results
- **CBC:** Hemoglobin 10.2 g/dL, WBC 11,200, Platelets 485,000 (reactive thrombocytosis)
- **CRP:** 48 mg/L (elevated)
- **Albumin:** 2.9 g/dL
- **Fecal Calprotectin:** 650 mcg/g (markedly elevated, indicates intestinal inflammation)
- **Colonoscopy:** Skip lesions with aphthous ulcers, cobblestone mucosa in terminal ileum and cecum; rectal sparing; deep ulcerations in terminal ileum
- **MR Enterography:** Thickened terminal ileum with mural enhancement and restricted diffusion; small mesenteric abscess (2 cm)
- **Histopathology:** Non-caseating granulomas, transmural inflammation

![Crohn's Disease Colonoscopy](case_01_image.jpg)
*Colonoscopic image of Crohn's disease showing characteristic cobblestone mucosa created by linear ulcerations intersecting with areas of edematous mucosa, and deep serpiginous ulcers in the terminal ileum.*

**Image Source:** Wikimedia Commons, CC BY-SA 3.0

### Diagnosis
**Crohn's Disease (Ileocolonic, Penetrating/Fistulizing Phenotype)**

### Clinical Correlation
Crohn's disease is a chronic inflammatory condition that can affect any portion of the GI tract from mouth to anus, with terminal ileum most commonly involved. Key distinguishing features from ulcerative colitis include: transmural inflammation (leading to strictures, fistulas, abscesses), skip lesions (non-contiguous involvement), rectal sparing, granulomas on histology, and perianal disease. Extraintestinal manifestations include arthritis (most common), aphthous ulcers, and skin/eye involvement. This patient's perianal fistula and mesenteric abscess indicate penetrating/fistulizing behavior, a more aggressive phenotype.

### Treatment
- Mesenteric abscess: CT-guided drainage + antibiotics (ciprofloxacin + metronidazole)
- Perianal fistula: MRI pelvis to characterize; surgical drainage of any abscess; seton placement
- Induction therapy: anti-TNF biologic (infliximab or adalimumab) given fistulizing disease
- Maintenance therapy: continue anti-TNF + consider adding immunomodulator (azathioprine)
- Nutritional support: enteral nutrition, vitamin/mineral supplementation
- Smoking cessation counseling (critical - smoking worsens Crohn's)
- Surveillance for strictures and malignancy

---

## Case 2: Ulcerative Colitis

### Patient Presentation
**Demographics:** 35-year-old male

**Chief Complaint:** Bloody diarrhea, urgency, and tenesmus for 3 weeks

**History of Present Illness:** The patient reports 8-10 bloody, mucoid stools daily with severe urgency and a constant feeling of incomplete evacuation (tenesmus). He has nocturnal bowel movements that wake him from sleep. He has crampy left-sided abdominal pain that precedes bowel movements. He has had a low-grade fever and has lost 8 pounds.

**Past Medical History:** None

**Social History:** Non-smoker (quit 2 years ago), social alcohol

### Physical Examination
- **Vital Signs:** BP 115/72 mmHg, HR 102 bpm, Temperature 38.1C, BMI 24
- **General:** Appears uncomfortable, mildly pale
- **Abdomen:** Mild left lower quadrant tenderness, hyperactive bowel sounds, no distension or peritoneal signs
- **Rectal:** Bright red blood on glove, no masses

### Workup and Results
- **CBC:** Hemoglobin 11.4 g/dL, WBC 13,500, Platelets 410,000
- **CRP:** 62 mg/L, ESR 48 mm/hr
- **Albumin:** 3.1 g/dL
- **Stool Studies:** Negative for C. difficile, bacterial pathogens, ova/parasites
- **Fecal Calprotectin:** 890 mcg/g
- **Colonoscopy:** Continuous inflammation from rectum extending to splenic flexure; erythema, edema, loss of vascular pattern, friability, and superficial ulcerations; clear demarcation at splenic flexure with normal proximal colon
- **Histopathology:** Crypt abscesses, crypt architectural distortion, inflammation limited to mucosa

![Ulcerative Colitis Colonoscopy](case_02_image.jpg)
*Colonoscopic appearance of active ulcerative colitis showing diffuse erythema, loss of normal vascular pattern, mucosal friability with contact bleeding, and superficial ulcerations. Note the continuous nature of inflammation.*

**Image Source:** Wikimedia Commons, CC BY-SA 3.0

### Diagnosis
**Ulcerative Colitis (Left-sided/Moderate-Severe)**

### Clinical Correlation
Ulcerative colitis is characterized by continuous mucosal inflammation beginning at the rectum and extending proximally. Key distinguishing features from Crohn's include: involvement limited to colon, always involves rectum, continuous (not skip) lesions, inflammation confined to mucosa and submucosa, crypt abscesses on histology, and absence of granulomas. The extent is classified as proctitis, left-sided (to splenic flexure), or pancolitis. Severity is assessed by Truelove-Witts criteria or Mayo score based on stool frequency, blood, endoscopic findings, and physician assessment. This patient has moderate-severe disease requiring systemic therapy.

### Treatment
- Exclude infection (stool studies including C. difficile)
- Induction therapy options for moderate-severe disease:
  - IV corticosteroids (methylprednisolone 40-60 mg daily) for acute flare
  - If steroid-refractory: infliximab or cyclosporine as rescue therapy
- Maintenance therapy: anti-TNF (infliximab, adalimumab), vedolizumab (gut-selective), or tofacitinib (JAK inhibitor)
- 5-ASA (mesalamine) may be added for maintenance but insufficient alone for this severity
- Assess for toxic megacolon (abdominal X-ray if suspected)
- Surgical consultation if medical therapy fails (colectomy is curative)
- Colonoscopic surveillance for dysplasia starting 8 years after diagnosis

---

## Case 3: Toxic Megacolon

### Patient Presentation
**Demographics:** 42-year-old male

**Chief Complaint:** Severe abdominal pain and distension with fever

**History of Present Illness:** The patient has a 10-year history of ulcerative colitis, currently on mesalamine. He was experiencing a moderate flare with bloody diarrhea for 2 weeks when symptoms abruptly changed 48 hours ago. His diarrhea decreased but was replaced by severe abdominal distension and pain. He developed high fever and feels very weak. He has had minimal bowel movements in the past day despite previous diarrhea.

**Past Medical History:** Pancolonic ulcerative colitis diagnosed 10 years ago

**Medications:** Mesalamine (admits to irregular adherence)

### Physical Examination
- **Vital Signs:** BP 88/55 mmHg, HR 128 bpm, Temperature 39.2C, RR 24/min
- **General:** Toxic-appearing, diaphoretic, altered mental status
- **Abdomen:** Markedly distended, diffusely tender with guarding, tympanitic, diminished bowel sounds
- **Rectal:** Empty vault, small amount of blood

### Workup and Results
- **CBC:** WBC 22,500 with bandemia, Hemoglobin 9.8 g/dL
- **BMP:** Na 132, K 2.8, Cr 1.8 mg/dL
- **Lactate:** 4.2 mmol/L (elevated)
- **Albumin:** 2.2 g/dL
- **Abdominal X-ray:** Transverse colon diameter 8 cm (>6 cm is diagnostic); loss of haustral markings; no free air
- **CT Abdomen:** Dilated colon with wall thickening and thumbprinting; no perforation; ascites present

![Toxic Megacolon X-ray](case_03_image.jpg)
*Abdominal X-ray demonstrating toxic megacolon with markedly dilated transverse colon (>6 cm diameter), loss of haustral markings, and mucosal irregularity (thumbprinting). This is a surgical emergency.*

**Image Source:** Case courtesy of Radiopaedia.org

### Diagnosis
**Toxic Megacolon Complicating Ulcerative Colitis**

### Clinical Correlation
Toxic megacolon is a life-threatening complication of IBD (and infectious colitis) defined by colonic dilation >6 cm with systemic toxicity. The inflammation extends transmurally, paralyzing colonic smooth muscle and causing dilation. The "paradoxical improvement" in diarrhea actually reflects colonic dysmotility, not healing. Criteria include colonic dilation plus at least 3 of: fever >38.5C, HR >120, WBC >10,500, and anemia. Risk of perforation is high, and mortality is significant. Contributing factors include electrolyte derangements (hypokalemia), opioid use, anticholinergics, and discontinuation of maintenance therapy.

### Treatment
- **Immediate ICU admission**
- Aggressive IV fluid resuscitation, correct electrolytes (especially potassium)
- NPO, nasogastric decompression
- Broad-spectrum antibiotics (piperacillin-tazobactam) to cover translocation
- IV corticosteroids (hydrocortisone 100 mg every 8 hours)
- Avoid opioids, anticholinergics, and antidiarrheals
- **Surgical consultation immediately** - colectomy if no improvement in 24-72 hours, or earlier if perforation, peritonitis, or massive hemorrhage
- Serial abdominal X-rays to monitor for progression or perforation
- If responsive to medical therapy, transition to infliximab or other biologic for maintenance