A 21-year-old woman comes to the physician because of a 4-day history of abdominal cramps and bloody diarrhea 5 times per day. Her symptoms began after she ate an egg sandwich from a restaurant. Her vital signs are within normal limits. Physical examination shows diffuse abdominal tenderness. Stool culture shows gram-negative rods that produce hydrogen sulfide and do not ferment lactose. Which of the following effects is most likely to occur if she receives antibiotic therapy?

Prolonged fecal excretion of the pathogen

Orange discoloration of bodily fluids

Pruritic maculopapular rash on the extensor surface

Self-limiting systemic inflammatory response

Thrombocytopenia and hemolytic anemia

A 22-year-old man presents to the emergency department with abdominal pain. The patient states that he has had right lower quadrant abdominal pain for "a while now". The pain comes and goes, and today it is particularly painful. The patient is a college student studying philosophy. He drinks alcohol occasionally and is currently sexually active. He states that sometimes he feels anxious about school. The patient's father died of colon cancer at the age of 55, and his mother died of breast cancer when she was 57. The patient has a past medical history of anxiety and depression which is not currently treated. Review of systems is positive for bloody diarrhea. His temperature is 99.5°F (37.5°C), blood pressure is 100/58 mmHg, pulse is 120/min, respirations are 17/min, and oxygen saturation is 98% on room air. Cardiopulmonary exam is within normal limits. Abdominal exam reveals diffuse tenderness. A fecal occult blood test is positive. Which of the following is the most likely diagnosis?

Inflammatory bowel disease (IBD)

A 31-year-old woman comes to the emergency department because of a 4-day history of fever and diarrhea. She has abdominal cramps and frequent bowel movements of small quantities of stool with blood and mucus. She has had multiple similar episodes over the past 8 months. Her temperature is 38.1°C (100.6°F), pulse is 75/min, and blood pressure is 130/80 mm Hg. Bowel sounds are normal. The abdomen is soft. There is tenderness to palpation in the left lower quadrant with guarding and no rebound. She receives appropriate treatment and recovers. Two weeks later, colonoscopy shows polypoid growths flanked by linear ulcers. A colonic biopsy specimen shows mucosal edema with distorted crypts and inflammatory cells in the lamina propria. Which of the following is the most appropriate recommendation for this patient?

Start annual colonoscopy starting in 8 years

Obtain barium follow-through radiography in 1 year

Obtain glutamate dehydrogenase antigen immunoassay now

Start annual magnetic resonance cholangiopancreatography screening in 10 years

A 34-year-old man with a 2-year history of rheumatoid arthritis is being evaluated on a follow-up visit. He is currently on methotrexate and celecoxib for pain management and has shown a good response until now. However, on this visit, he mentions that the morning stiffness has been getting progressively worse. On physical examination, both his wrists are erythematous and swollen, nodules on his elbows are also noted. Rheumatoid factor is 30 (normal reference values: < 15 IU/mL), ESR is 50 mm/h, anti-citrullinated protein antibodies is 55 (normal reference values: < 20). What is the next best step in the management of this patient?

Methotrexate and Corticosteroids

Medical management of ulcerative colitis for USMLE Step 1: High-Yield Internal Medicine Lessons

UC Severity & Goals - Gauging the Gut Fire

Primary Goals: Induce and maintain clinical remission AND achieve endoscopic healing (mucosal normalization).

Severity	Stools/Day (Bloody)	Systemic Toxicity Signs
Mild	<4	None
Moderate	4-6	Minimal (e.g., low-grade fever)
Severe	>6	Fever >37.8°C, HR >90, ESR >30, Hb <10.5 g/dL

⭐ Exam Pearl: Endoscopic healing is a critical treatment goal beyond symptom control; it correlates with lower rates of hospitalization and colectomy.

Mild-Moderate UC - Calming the Waters

Goal: Induce & maintain remission.
First-line: 5-Aminosalicylates (5-ASA) (e.g., Mesalamine) are the mainstay, acting topically on the colonic mucosa.

⭐ Sulfasalazine, an older 5-ASA, is less favored due to sulfa-related side effects (rash, hemolysis in G6PD deficiency) and impaired folate absorption. Always co-prescribe folic acid if used.

📌 SulfaSalazine Side effects: Stevens-Johnson, Skin rash, Sperm problems, Sulfa allergy.

Moderate-Severe UC - Calling in the Big Guns

Initial Therapy: Hospitalization & IV corticosteroids (e.g., methylprednisolone) are first-line for acute flares.
If No Response in 3-5 days:
- First, rule out superimposed CMV colitis via biopsy with IHC.
- Then, escalate to advanced therapies.
Advanced Therapies (Induction & Maintenance):
- Anti-TNF agents: Infliximab, Adalimumab, Golimumab.
- Anti-integrin: Vedolizumab (gut-selective).
- JAK inhibitors: Tofacitinib, Upadacitinib (oral option).
- Immunomodulators: Azathioprine/6-MP are steroid-sparing but have a slow onset.

⭐ Before starting thiopurines (Azathioprine/6-MP), check TPMT (thiopurine methyltransferase) activity to prevent severe myelosuppression.

Endoscopic Ulcerative Colitis Severity Scale

Maintenance Therapy - Keeping the Peace

Goal: Prolong remission & reduce flare frequency/severity.
Mild-Moderate UC:
- 5-ASA agents (Mesalamine, Sulfasalazine) are the cornerstone; oral +/- rectal formulations are used.
Moderate-Severe or Steroid-Dependent UC:
- Thiopurines: Azathioprine (AZA) or 6-mercaptopurine (6-MP).
- Biologics & Small Molecules: Anti-TNF agents (Infliximab, Adalimumab), anti-integrin (Vedolizumab), IL-12/23 inhibitor (Ustekinumab), or JAK inhibitors (Tofacitinib) for refractory disease.

⭐ TPMT testing is crucial before starting thiopurines (AZA/6-MP) to identify patients at high risk for life-threatening myelosuppression due to impaired drug metabolism.

High‑Yield Points - ⚡ Biggest Takeaways

Mesalamine (5-ASA) is the cornerstone for inducing and maintaining remission in mild-to-moderate ulcerative colitis.

Corticosteroids are used for acute flares but are not suitable for long-term maintenance due to side effects.

Thiopurines (azathioprine, 6-MP) serve as steroid-sparing maintenance therapy.

Anti-TNF agents (infliximab) and vedolizumab are key for moderate-to-severe or refractory disease.

Always test for C. difficile infection before escalating immunosuppressive therapy during a flare.

Toxic megacolon requires immediate cessation of offending drugs and urgent surgical consultation.

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