John Clarke, MD
Gastroenterology · Palo Alto, CANPI 1467539643
Payments from drug & device makers
Across 29 payments — averaging $1317.67 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Sanofi US Services Inc.$16K
- Pfizer$9K
- Ironwood Pharmaceuticals, Inc$8K
- Alnylam Pharmaceuticals Inc.$3K
- AstraZeneca$2K
- Medtronic$394
- plus $361 from 6 others
Across 10 payments — averaging $1737.50 each. Payments tied to a research study. These frequently flow through the physician to a hospital or research institution rather than to the physician personally.
- Regeneron$10K
- Medtronic$8K
What the payments were for
- Consulting fees$19,90266%
- Speaking & faculty fees$8,50028%
- Travel & lodging$7863%
- Food & beverage$9033%
General payments by program year
Who reported the general payments
Companies are grouped under their corporate parent — a single manufacturer often files under several CMS reporting entities. Research and ownership payments are counted separately and are not in this table.
| Company | Payments | Total |
|---|---|---|
| Sanofi US Services Inc. | 8 | $15,561 |
| Pfizer | 2 | $8,500 |
| Ironwood Pharmaceuticals, Inc | 6 | $8,122 |
| Alnylam Pharmaceuticals Inc. | 1 | $3,375 |
| AstraZeneca | 1 | $1,900 |
| Medtronic | 5 | $394 |
| Boston Scientific | 1 | $149 |
| Phathom Pharmaceuticals, Inc. | 1 | $100 |
| Bracco Diagnostics Inc. | 1 | $40 |
| Mauna Kea Technologies, Inc. | 1 | $29 |
| Akcea Therapeutics, Inc. | 1 | $24 |
| Regeneron Healthcare Solutions, Inc. | 1 | $19 |
What the payments were tied to
Products named in the reported payments. Only payments of $100 or more are attributed here — the typical reported payment nationally is a meal worth about $16, and listing those product-by-product would be noise.
How this compares
$38,212 in reported general payments places this provider in the 85th percentile of 1,885 gastroenterology providers in California.
Medicare billing
What this is not: this is the amount Original Medicare Part B allowed for services this provider billed in 2024. It is not their income. It excludes Medicare Advantage — now more than half of all Medicare enrollment — along with Medicaid and all commercial insurance, and it is gross practice revenue before staff, rent, supplies and malpractice premiums. CMS also suppresses any figure covering ten or fewer patients, so low-volume providers appear smaller than they are.
Most prescribed under Part D
| Drug | Claims | Cost to plans & patients |
|---|---|---|
| XifaxanRifaximin | 26 | $73,487 |
| MotegrityPrucalopride Succinate | 54 | $50,815 |
| LinzessLinaclotide | 41 | $39,429 |
| Dexlansoprazole DrDexlansoprazole | 76 | $29,566 |
| TrulancePlecanatide | 16 | $13,590 |
| Esomeprazole Magnesium | 53 | $7,011 |
| Pantoprazole Sodium | 87 | $4,019 |
| Sucralfate | 11 | $1,563 |
| Peg 3350-ElectrolyteSodium Chloride/Nahco3/Kcl/Peg | 41 | $894 |
| Famotidine | 53 | $829 |
| Omeprazole | 65 | $773 |
| Mirtazapine | 17 | $732 |
| Ondansetron OdtOndansetron | 13 | $720 |
| Pyridostigmine Bromide | 16 | $614 |
| Baclofen | 15 | $313 |
Paid to pharmacies, not to this prescriber.
Other gastroenterology in Palo Alto
- Peter WinkleCypress$116.7M
- Manuchehr DaraniSanta Ana$17.7M
- Jatinder PruthiLancaster$4.4M
- Long DangWestminster$4.3M
- Muhammad SheikhFresno$4.3M
- Gregory WienerChula Vista$3.5M
- Gil MelmedLos Angeles$3M
- Christopher BowlusSacramento$3M
- Bennett RothLos Angeles$2.8M
- Brigid BolandSan Diego$2.4M
Where these figures come from
- Payments: CMS Open Payments, program years 2019–2025 (publication P06302026_06032026).
- Billing: Medicare Physician & Other Practitioners, data year 2024. Original Medicare Part B only.
- Identity: NPPES NPI Registry, July 2026.