Episode one of the GI in Pregnancy chapter sets the physiologic baseline that every later stem depends on. The organizing idea is that pregnancy shifts a predictable set of labs, so any deviation pregnancy does not itself cause is by definition pathologic. From there it walks the volume, CBC, and liver-test changes, the fetal-protective imaging menu, and the antiemetic sequence for nausea and hyperemesis. The through-line is that you interpret a pregnant patient against a moved reference range, and you treat vomiting on a mechanistic ladder that ends with an absolute safety rule.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI in Pregnancy

Read this episode: boardpearls.com/gi/episodes/gi-in-pregnancy-ep1

Questions or feedback: [email protected].

• (00:00) - Introduction and the shifted-baseline principle

Episode four closes the module on checkpoint inhibitor toxicity, one entity with many organ targets, where releasing the brakes on T cells means the same cells recognize self. Drug class predicts the toxicity rate, with anti-CTLA-4 broad and severe, anti-PD-1 focal and milder, and combination highest, while grade drives therapy through a universal seventy-two-hour escalation window. The colitis algorithm runs grade-based steroids then infliximab or vedolizumab, with the choice turning on hepatic comorbidity and CMV risk. The single most tested distinction is that steroid-refractory hepatitis goes to mycophenolate mofetil, not infliximab, because infliximab is contraindicated by its own hepatotoxicity, and the whole framework extends to pneumonitis, endocrinopathies, and the other immune-related adverse events.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI in the Immunocompromised Host

Read this episode: boardpearls.com/gi/episodes/gi-in-the-immunocompromised-ep4

Questions or feedback: [email protected].

• (00:00) - One entity, many organ targets

Episode three covers the non-transplant immunocompromised GI host, where two settings that look unrelated share one logic: identify the host state, and the host state opens a tiered differential. In HIV that state is the CD4 count, which converts a long pathogen list into strata that drive workup and surfaces the pre-antiretroviral-era entities still seen in late presenters, AIDS cholangiopathy, gut Kaposi sarcoma, and post-treatment IRIS. In chemotherapy-related neutropenia that state is the absolute neutrophil count, which defines typhlitis as a cecum-predominant enterocolitis managed conservatively with bowel rest and broad-spectrum antibiotics. The recurring move is that the number tells you what to look for and the entity tells you what to do, from antiretroviral therapy as the dominant intervention to the narrow list of surgical indications.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI in the Immunocompromised Host

Read this episode: boardpearls.com/gi/episodes/gi-in-the-immunocompromised-ep3

Questions or feedback: [email protected].

• (00:00) - Two host states, one recognition logic

Episode two takes the other host state hiding behind the word transplant: the hematopoietic cell transplant recipient whose donor immune system attacks the host. The post-transplant timeline organizes everything, with the first twenty-one days belonging to conditioning toxicity rather than graft-versus-host disease, so the timeline decides which diagnosis is even allowed. Gut disease is staged by daily stool volume on the Glucksberg-Seattle thresholds, the histology anchors on crypt apoptosis, and the biopsy-bench differential always includes CMV because apoptosis is not pathognomonic. Treatment is methylprednisolone first and ruxolitinib second on the strength of a randomized trial, and the shared move across both host states is to pair every immunosuppression escalation with an infectious workup.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI in the Immunocompromised Host

Read this episode: boardpearls.com/gi/episodes/gi-in-the-immunocompromised-ep2

Questions or feedback: [email protected].

• (00:00) - The other transplant and the post-transplant timeline

Episode one of the GI in the Immunocompromised Host chapter starts with a single recognition move: a transplant recipient on calcineurin inhibitor plus mycophenolate plus prednisone with diarrhea could be any of five entities at once, and time since transplant is the variable that reorders the differential. The first month belongs to the surgeon, the one-to-twelve-month window belongs to opportunistic infection, and beyond a year belongs to cumulative toxicity and malignancy. From there the reasoning runs on enzymes: donor-recipient serostatus and UL97 versus UL54 for CMV resistance, CYP3A4 for the calcineurin inhibitor trap, and dose-dependent crypt exposure for mycophenolate enteropathy. Sitting over all of it, Epstein-Barr virus drives the post-transplant lymphoproliferative disorder that responds first to reducing the immunosuppression that allowed it.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI in the Immunocompromised Host

Read this episode: boardpearls.com/gi/episodes/gi-in-the-immunocompromised-ep1

Questions or feedback: [email protected].

• (00:00) - The five-entity differential and the organizing idea

The immunocompromised gut expands the pathogen list, and the organizing move is that each organism lives behind a specific cue that names the therapy: name the host, the stain, and the histology, and you name the drug. CMV gives the owl-eye inclusion at the ulcer base treated with ganciclovir, with foscarnet as salvage when UL97 mutations break the prodrug pathway. MAC gives the PAS-positive, acid-fast-positive macrophage treated with a macrolide plus ethambutol, microsporidia turn on beta-tubulin pharmacology, and the coccidians answer to trimethoprim-sulfamethoxazole. The unifying thread is that antimicrobials hold the line while immune reconstitution provides durable clearance.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI Infections

Read this episode: boardpearls.com/gi/episodes/gi-infections-ep5

Questions or feedback: [email protected].

• (00:00) - Introduction: cue points to drug

The parasitic diarrheas sort by exposure history, so the workup follows the suspected pathogen rather than a generic ova-and-parasite exam. Giardia comes from untreated water with a single-dose tinidazole answer, Entamoeba histolytica from endemic travel with two-stage tissue-then-luminal therapy, and Strongyloides is the pre-steroid serology question that prevents seventy-percent-mortality hyperinfection. Anisakis is the raw-fish larva cured by endoscopic removal. On the viral side, norovirus dominates on infectious dose and environmental persistence, which is why soap-and-water and bleach are the outbreak answers, while rotavirus fades under vaccination.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI Infections

Read this episode: boardpearls.com/gi/episodes/gi-infections-ep4

Questions or feedback: [email protected].

• (00:00) - Introduction and exposure-based workup

The community-acquired diarrheas separate cleanly once you group by acquisition pattern rather than symptoms, because the exposure history predicts the pathogen and the pathogen predicts the treatment. Travelers' diarrhea selects the empiric antibiotic by region and resistance, while rifaximin stays in the noninvasive niche because it is non-absorbed. Shiga-toxin-producing E. coli flips the rule entirely, since antibiotics release more toxin and loperamide prolongs exposure. Nontyphoidal Salmonella, Shigella, Yersinia, Vibrio, and Listeria each run on their own biology, and the foodborne toxin syndromes are recognized by time to onset that tells you cultures and antibiotics are unnecessary.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI Infections

Read this episode: boardpearls.com/gi/episodes/gi-infections-ep3

Questions or feedback: [email protected].

• (00:00) - Introduction and acquisition pattern

Recurrence is the dominant management problem in C. diff, and this episode organizes the entire toolkit around a single mechanism: the spore. Surviving spores germinate once the antibiotic stops, so every tool either keeps colonic drug above the killing threshold across successive germination waves or restores the commensal community that denies spores a niche. The drug you reach for depends on what was used first, the structural taper-and-pulse pattern matters more than the molecule, and after two or more recurrences the strategy shifts from antibiotics to microbiome restoration. Bezlotoxumab and prophylaxis close the loop in the right patients.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI Infections

Read this episode: boardpearls.com/gi/episodes/gi-infections-ep2

Questions or feedback: [email protected].

• (00:00) - Introduction and the spore mechanism

Episode one of the GI Infections chapter builds C. diff around two competing problems: the defaults moved off metronidazole and vancomycin, and asymptomatic colonization is common enough that the wrong test drives unnecessary treatment. The organizing idea is that diagnosis exists to separate active disease from colonization, while treatment exists to get the right drug to the colonic lumen at the right concentration for the right duration. Severity thresholds decide treatment intensity, and fulminant features bring surgery into the conversation at presentation rather than after medical failure. Everything reduces to those two problems.

Topics covered

Key decisions

Study the full chapter on Board Pearls, with practice questions, tables and primary-guideline references: GI Infections

Read this episode: boardpearls.com/gi/episodes/gi-infections-ep1

Questions or feedback: [email protected].

• (00:00) - Introduction and the two organizing problems