Questions to Ask a Gastroenterology Expert Witness at Deposition (2026 Guide)

By John Mahoney · Updated 2026-09-01 · 18 questions in 4 concession chains

You are about to cross-examine someone with two decades of training you don't have, on their home turf, about the thing they do every day. That asymmetry is the defining problem of medical-expert depositions — and it gets worse in multi-defendant malpractice cases, where two to four different specialties can be in play in a single case and you have to be conversant in all of them by deposition day.

Gastroenterology experts testify on colonoscopy complications, missed lesions and interval cancers, and GI bleeding. The "known complication" defense and the "interval cancers happen" defense both dissolve when the exam-quality and recognition questions are asked separately and in order.

The answer to the asymmetry is not to learn gastroenterology — it is structure. A concession funnel asks the expert to agree, one fact at a time, to propositions so orthodox that refusing them costs more credibility than granting them. The questions below are a generic-case-safe starting bank, organized into the four chains that structure works through.

How to use these questions

Every question below follows three rules of expert cross-examination: it is leading (it states a fact and asks for agreement), it contains one fact (no compounds — a compound question lets the witness answer the easy half), and it belongs to a concession chain (each answer narrows the room the next answer can live in). Ask them in order. When you get the concession, stop — do not ask the "why" question that lets the expert explain it away.

Chain 1 — Qualifications, retention & scope

Goal: establish on the record that this is a paid, retained witness who never touched the patient, and fix the boundaries of what they actually practice.

Doctor, you were retained by opposing counsel in this case, correct?
You are being compensated for your time reviewing this case and for your testimony today, correct?
You never examined or treated the patient in this case, correct?
Everything you know about this case comes from the materials counsel selected and sent to you, correct?
The quality of an endoscopic examination depends in part on conditions during the exam — such as the quality of the prep and the visibility achieved, correct?

Chain 2 — Bases-of-opinion lockdown

Goal: freeze the universe. After this chain, any new document, new basis, or new opinion at trial is impeachment material.

You have now told us every document and material you reviewed in forming your opinions, correct?
You are not relying on anything outside that file for the opinions you will give in this case, correct?
You have told us every opinion you intend to offer at trial, correct?
You agree that an opinion you cannot state to a reasonable degree of medical probability is speculation, correct?

Chain 3 — Substantive concessions: procedure quality and complication recognition

These concessions separate the two things gastroenterology cases actually turn on: whether the exam was adequate, and whether the complication was recognized in time.

Perforation is a recognized complication of colonoscopy, correct?
Recognizing a perforation promptly is part of the standard of care, correct?
Severe or worsening abdominal pain after an endoscopic procedure requires evaluation, correct?
A gastrointestinal bleed can be life-threatening, correct?
If visibility during a colonoscopy is poor, that limitation should be documented, correct?
An incomplete examination is different from a normal examination, correct?

Chain 4 — Closing the doors

Goal: end with the record sealed. These questions convert silence into a commitment that nothing new is coming at trial.

You are not offering any opinions in this case beyond the ones we have discussed today, correct?
You have not held back any opinion or criticism that you intend to offer at trial, correct?
You are not offering any opinion about the anesthesia or sedation care during the procedure, correct?

These are the generic questions. Your case isn't generic.

The MedLegal AI Examination Builder generates a complete, case-specific concession-funnel roadmap for deposing a gastroenterology expert — built from your theory of the case, aware of which side you're on and what kind of witness you're facing, with stop markers, if-they-resist branches, and the doors you should not open. Three free cases, no credit card.

Build my examination → Gastroenterology depo trainer

Where lawyers get burned deposing gastroenterology experts

Letting "complication, not negligence" absorb the recognition delay

The perforation itself may be defensible; the eighteen hours of worsening pain before anyone acted usually is not. Experts answer the complication question and hope you never separately ask the recognition question. Two chains, asked separately, in that order.

Arguing interval cancer without pinning exam quality

When a cancer appears after a "normal" colonoscopy, the defense says interval cancers are a known phenomenon. They are — after an adequate exam. Lock what the procedure report documents about prep quality, completeness, and visibility first. An interval-cancer defense built on an undocumented-quality exam is a different case.

Getting pulled into the sedation-consent sideshow

GI depositions drift into sedation consent details that rarely decide the case. Unless consent is your theory, take the standard concessions and return to the exam-quality and recognition chains where the case actually lives.

FAQ

What questions should I ask a gastroenterology expert witness at deposition?

Work in four concession chains: (1) qualifications, retention, and scope — establish the expert was retained, is compensated, never treated the patient, and what they do and do not practice; (2) bases-of-opinion lockdown — pin every document reviewed and every opinion they intend to offer; (3) the gastroenterology-specific substantive chain — well-established propositions such as "Perforation is a recognized complication of colonoscopy"; and (4) closing the doors — confirm on the record that no undisclosed opinions remain. Every question should be leading, contain one fact, and build on the prior answer.

How do I cross-examine a medical expert when I never went to medical school?

You don't out-doctor the doctor — you build concession chains from propositions so well-established that a credible gastroenterology expert cannot refuse them, then apply those concessions to the facts in the chart. The expert's medical training becomes your asset: the more orthodox the proposition, the more it costs them to fight it. The asymmetry problem is real — especially in multi-defendant cases with two to four specialties — which is why the questions are organized as funnels rather than as debates.

What are the biggest traps when deposing a gastroenterology expert witness?

The classic traps are letting the "known complication" answer absorb a separate delayed-recognition failure, arguing about interval cancers before locking what the report documents about prep quality and completeness, and losing deposition hours to sedation-consent side issues that are not the theory of the case.

Related resources

Examination Builder — a case-specific concession-funnel roadmap from your theory of the case
Gastroenterology deposition trainer — the other side of the table: how gastroenterology witnesses are prepped against these questions
All specialties — deposition question guides
Are you a gastroenterology physician? Join the MedLegal AI expert network

This page is informational only and is not legal advice. Question banks are generic-case-safe starting points — adapt every question to the facts, the jurisdiction, and your theory of the case before using it in a deposition.