SystemWise Micro · Gastrointestinal

24 organisms.
One method.

You are not revising all of microbiology today. You are revising the 24 organisms that belong to gastrointestinal — the exact list is below — and you are doing each one the same way. That method is WRWRT.

Why this page exists

Opening the SystemWise Micro chart and scanning the whole image is how an hour disappears without a single organism being revised. The list has already been made for you. Work down it, apply WRWRT to each one, and stop when it ends.

Never done Sketchy? Read this first

If you have only ever used First Aid, you can revise every organism on this page from First Aid and the FA Guide alone. The list below is still your list; only the source changes. You will not fail for skipping Sketchy.

But if you have the time, invest in Sketchy — or whichever video resource is named against each organism. The whole point of a named resource is that somebody already worked out which one teaches that organism best, so you do not spend an evening sampling three of them. Sketchy is a memory palace; First Aid is a reference. If you can afford the hours, use both.

PART ONEThe WRWRT method

Five steps, in order, for every organism. The order is the whole point: each step only works because of the one before it.

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Watch

1x speed. Full attention. No notes. Notes split your attention, and your brain cannot process the visual story and write at the same time. Just watch.

Why: the sketch is a memory palace. You are walking through a building, not collecting facts. Pausing to write is stopping at the door of every room.
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Recall

Close the video. Look away from the screen. Walk the whole story through chronologically, in your head — start to finish, in order.

Why: this is the step everyone skips and the only one that builds retrieval. The struggle is the method. If it feels uncomfortable it is working; if it feels easy, you are recognising, not recalling.
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Watch again

1.5x or 1.75x, and only the parts you could not recall — not the whole video again. Fill the gaps, then move on.

Why: rewatching what you already knew feels productive and teaches you nothing. Your failed recall just told you exactly where to spend the time.
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Read the PDF

Open the Sketchy Micro PDF for those organisms — the written version of what you just watched. Read it once.

Why: the exam asks in words, not pictures. This converts the image into sentences you can actually retrieve under a question stem.
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Test

Finish with the FA Guide MCQs for those exact organisms, in the Microbiology section — not the whole of Micro, just what you covered.

Why: if you cannot answer them, you watched — you did not learn. This is the only step that tells you the truth about the previous four.
Completion over perfection

The goal is not to master gastrointestinal microbiology today. It is to finish these 24 and move on. The real learning happens when you meet these organisms in UWorld weeks from now and the visual story comes straight back.

PART TWOThe 24 gastrointestinal organisms

This is the entire gastrointestinal column of the SystemWise Micro chart. Nothing else from Micro belongs to this system, and nothing here belongs to another one.

Bacteria · 14
  1. 01Vibrio cholerae
  2. 02Enterotoxigenic E. coli (ETEC)
  3. 03Staphylococcus aureus
  4. 04Clostridium perfringens
  5. 05Bacillus cereus
  6. 06Shigella
  7. 07Enterohaemorrhagic E. coli (EHEC)
  8. 08Enteroinvasive E. coli (EIEC)
  9. 09Salmonella — especially non-typhoidal
  10. 10Campylobacter jejuni
  11. 11Yersinia enterocolitica
  12. 12Clostridioides difficile
  13. 13Helicobacter pylori — gastritis, peptic ulcer, MALT lymphoma
  14. 14Clostridium botulinum — ingested toxin; the illness itself is neuroparalytic (see CNS)
Viruses · 7
  1. 15Norovirus
  2. 16Rotavirus
  3. 17Adenovirus
  4. 18Cytomegalovirus — especially immunocompromised
  5. 19Herpes simplex virus — especially immunocompromised
  6. 20Hepatitis A virus (HAV) — faeco-oral, acute only
  7. 21Hepatitis B virus (HBV) — sexual/perinatal; can become chronic
Parasites · 3
  1. 22Giardia lamblia
  2. 23Cryptosporidium parvum
  3. 24Entamoeba histolytica
Four exceptions, across all of Sketchy

TB, COVID, HIV and the Bunyaviruses are done directly from First Aid, not from Sketchy. Skip them in Sketchy entirely.

PART THREEOne organism, worked through

Here is WRWRT applied to the first organism on the list, in full, so you know exactly what each step looks like before you do it 23 more times.

Worked example · 01 of 24 Vibrio cholerae
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Watch the Vibrio cholerae sketch, once, at 1x

Phone away. Nothing in your hands. You are watching a story, and you will be asked to retell it in about four minutes.

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Close it and retell the story out loud

Not a fact list — the sketch, in the order it happened. Then check yourself against the prompts below. If you cannot answer one, that is a gap, not a failure.

You should be able to say, without looking Shape and stain · what it does to make you sick — toxin, enzyme, capsule · who gets it, and after what · the one association the exam always builds the stem around · how it is treated
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Rewatch only the gaps

Whatever did not come back, scrub to that part of the sketch. 1.75x. Ninety seconds, not nine minutes. Then stop.

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Read the Vibrio cholerae pages of the Sketchy Micro PDF

Once, properly. Highlight only what you failed to recall a moment ago — those highlights are a precise map of where your memory breaks, and they are what you revisit before the exam. Everything else you already have.

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Do the FA Guide MCQs for Vibrio cholerae

Microbiology section, this organism only. Getting one wrong here costs you two minutes and fixes the gap permanently; the same gap found on test day costs you the mark.

Then repeat, 23 more times

That is one organism. Do the same for Enterotoxigenic E. coli (ETEC), Staphylococcus aureus, Clostridium perfringens, Bacillus cereus, Shigella, Enterohaemorrhagic E. coli (EHEC), Enteroinvasive E. coli (EIEC), Salmonella, Campylobacter jejuni, Yersinia enterocolitica, Clostridioides difficile, Helicobacter pylori, Clostridium botulinum, Norovirus, Rotavirus, Adenovirus, Cytomegalovirus, Herpes simplex virus, Hepatitis A virus (HAV), Hepatitis B virus (HBV), Giardia lamblia, Cryptosporidium parvum and Entamoeba histolytica — and gastrointestinal micro is finished. Do not go back to the chart. Do not start another system's organisms. Close this and move to your gastrointestinal First Aid reading.

Open the FA Guide → Microbiology Go to Gastrointestinal in the FA Guide
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