← All chapters
Cross-Cutting· Chapter 34

GI in the Immunocompromised Host

Solid-organ transplant GI (CMV, PTLD, post-transplant GVHD), HIV GI manifestations stratified by CD4, checkpoint-inhibitor colitis per NCCN and SITC, neutropenic enterocolitis decisions, GI graft-versus-host disease grading and management, and CAR-T toxicity.

Sign in to study →
26 MCQs
  • Audio chapter
    Attending-narrated, listen on the commute.
  • ABIM-format MCQs
    5-option vignettes with full wrong-answer teaching.
  • Study guide
    Tables, decision trees, primary sources.
  • AI tutor
    Chapter-grounded, answers the question you're stuck on.

What this chapter covers

  • Section 34.1: Solid organ transplant GI disease

    Solid organ transplant recipients carry a five-drug differential at every GI symptom: cytomegalovirus, mycophenolate enteropathy, calcineurin inhibitor toxicity, post-transplant lymphoproliferative disorder driven by Epstein-Barr virus, and Clostridioides difficile.

  • Section 34.2: HCT and acute gut graft-versus-host disease

    Approximately 20,000 allogeneic hematopoietic cell transplants are performed in the United States each year.

  • Section 34.3: HIV host framework and HIV-era GI

    This section focuses on the HIV host framework and the GI presentations that are framework-driven rather than pathogen-specific.

  • Section 34.4: Checkpoint inhibitor colitis

    Immune checkpoint inhibitors targeting CTLA-4 (ipilimumab, tremelimumab) and PD-1 or PD-L1 (nivolumab, pembrolizumab, cemiplimab, atezolizumab, durvalumab) unleash T-cell responses against tumor antigens but also against self tissue.

  • Section 34.5: Checkpoint inhibitor hepatitis and other irAEs

    Checkpoint inhibitor hepatitis affects approximately 4 to 9 percent of patients on anti-CTLA-4 monotherapy, 1 to 4 percent on anti-PD-1 or anti-PD-L1 monotherapy, and up to 18 percent on combination ipilimumab plus nivolumab.

  • Section 34.6: Neutropenic enterocolitis (typhlitis)

    Neutropenic enterocolitis presents in patients with absolute neutrophil count below 500 cells per microliter (especially under 100) receiving cytotoxic chemotherapy, most often during acute leukemia induction (cytarabine for acute myeloid leukemia, intensive regimens for pediatric acute lymphoblastic leukemia).

Podcast episodes

  1. 01

    Solid Organ Transplant

    This episode covers solid organ transplant GI disease: the five-entity diarrhea differential narrowed by time since transplant, CMV colitis with its resistance pathway, mycophenolate enteropathy, calcineurin inhibitor toxicity and its drug interactions, and post-transplant lymphoproliferative disorder.

  2. 02

    HCT GVHD

    This episode covers hematopoietic cell transplant gut graft-versus-host disease: the post-transplant timeline that decides which diagnosis is even allowed, gut GVHD graded by stool volume with skin and liver involvement, the crypt-apoptosis histology and its differential, and treatment with corticosteroids first and ruxolitinib for steroid- refractory...

  3. 03

    HIV and Typhlitis

    This episode covers HIV-era GI disease and neutropenic enterocolitis: the CD4-stratified opportunistic infection differential, the ART-related GI effects and post-ART immune reconstitution syndrome, and typhlitis as the chemotherapy-related neutropenic enterocolitis with conservative management for stable patients and surgery reserved for perforation,...

  4. 04

    Checkpoint Toxicity

    This episode covers checkpoint inhibitor toxicity: ICI colitis with grade-based corticosteroids then infliximab or vedolizumab for refractory disease, ICI hepatitis with the typical onset window and management that holds checkpoint inhibitors and starts steroids based on transaminase grade, and the irAE recognition framework across pneumonitis,...