Dennis Riff, MD
Gastroenterology · Anaheim, CANPI 1922004662
Payments from drug & device makers
What this record shows
The money is spread across several categories — speaking fees (46.0%), food and beverage and travel and lodging — rather than concentrated in one kind of arrangement. 32 manufacturers reported payments, led by Phathom Pharmaceuticals, Inc. at 54.6% of the total. Reporting peaked in 2024 at $22,593 and has fallen 90.2% since, to $2,205 in 2025. Among gastroenterology clinicians in CA with any reported payments, this total sits in the top 10% — high for the specialty, which is a reason to read the composition above rather than the number alone.
Across 665 payments — averaging $49.15 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Phathom Pharmaceuticals, Inc.$18K
- Olympus America Inc.$3K
- AbbVie$3K
- Pfizer$3K
- Salix Pharmaceuticals, A Division Of Bausch Health US, LLC$2K
- Ardelyx, Inc.$976
- plus $4K from 26 others
Across 2 payments — averaging $5521.44 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.
- Eli Lilly$11K
What the payments were for
- Speaking & faculty fees$15,05046%
- Travel & lodging$2,9109%
- Food & beverage$11,92536%
- Education$910%
- Other$2,7078%
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 |
|---|---|---|
| Phathom Pharmaceuticals, Inc. | 42 | $17,851 |
| Olympus America Inc. | 1 | $2,707 |
| AbbVie | 161 | $2,612 |
| Pfizer | 53 | $2,596 |
| Salix Pharmaceuticals, A Division Of Bausch Health US, LLC | 138 | $2,103 |
| Ardelyx, Inc. | 47 | $976 |
| Gilead | 33 | $826 |
| Takeda Pharmaceuticals U.S.A., Inc. | 73 | $714 |
| Johnson & Johnson | 35 | $675 |
| Sanofi | 11 | $294 |
| Madrigal Pharmaceuticals | 17 | $259 |
| Lilly USA, LLC | 5 | $186 |
| Intercept Pharmaceuticals, Inc. | 7 | $134 |
| Redhill Biopharma Inc. | 6 | $108 |
| QOL Medical, LLC | 5 | $86 |
| Bristol Myers Squibb | 4 | $83 |
| Organon | 4 | $65 |
| Shionogi Inc | 3 | $55 |
| Vivus LLC | 2 | $43 |
| Ironwood Pharmaceuticals, Inc | 3 | $41 |
| Amgen | 2 | $37 |
| Braintree Laboratories, Inc. | 2 | $32 |
| Aimmune Therapeutics, Inc. | 2 | $27 |
| Biocon Biologics Inc | 1 | $27 |
| Intra-sana Laboratories | 1 | $22 |
| Ipsen Biopharmaceuticals, Inc | 1 | $21 |
| Nestle Healthcare Nutrition Inc. | 1 | $19 |
| Novo Nordisk | 1 | $18 |
| Ferring Pharmaceuticals Inc. | 1 | $18 |
| Exact Sciences | 1 | $16 |
| Celltrion USA Inc. | 1 | $14 |
| Shield Therapeutics Inc | 1 | $14 |
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.
- VOQUEZNA$17,230
- EVIS X1 VIDEO SYSTEM CENTER$2,707
- PREVNAR - 13$1,411
- Skyrizi$372
- Epclusa$125
- Rinvoq$124
- OMVOH$121
- DUPIXENT$120
How this compares
$32,682 in reported general payments places this provider in the 90th 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 |
|---|---|---|
| Humira(Cf) PenAdalimumab | 19 | $271,146 |
| XifaxanRifaximin | 33 | $101,257 |
| LinzessLinaclotide | 95 | $69,944 |
| CreonLipase/Protease/Amylase | 24 | $63,077 |
| ZenpepLipase/Protease/Amylase | 16 | $52,364 |
| RezdiffraResmetirom | 11 | $47,959 |
| VemlidyTenofovir Alafenamide | 12 | $17,165 |
| Sod Sulf-Potass Sulf-Mag SulfSodium, Potassium,mag Sulfates | 259 | $16,117 |
| VoqueznaVonoprazan Fumarate | 11 | $15,035 |
| SutabSod Sulf/Pot Chloride/Mag Sulf | 78 | $12,473 |
| TrulancePlecanatide | 19 | $11,548 |
| Mesalamine | 27 | $8,756 |
| Pantoprazole Sodium | 322 | $4,585 |
| Omeprazole | 320 | $3,576 |
| PlenvuPeg3350/Sod Sul/Nacl/Kcl/Asb/C | 13 | $1,710 |
Paid to pharmacies, not to this prescriber.
Companies that both paid and supply prescribed drugs
These companies both reported payments to this provider and make drugs the provider prescribed under Medicare Part D in 2024. For most specialties this overlap is expected — a cardiologist who is paid by a cardiology drugmaker also treats heart disease. It is shown so the reader can see it, not because it implies anything on its own.
| Company | Paid to this provider | Part D cost of their drugs |
|---|---|---|
| AbbVieLinzess, Creon | $2,612 | $133,021119 claims |
| Salix Pharmaceuticals, A Division Of Bausch Health US, LLCXifaxan, Trulance, Plenvu | $2,103 | $114,51465 claims |
| Aimmune Therapeutics, Inc.Zenpep | $27 | $52,36416 claims |
| Madrigal PharmaceuticalsRezdiffra | $259 | $47,95911 claims |
| GileadVemlidy | $826 | $17,16512 claims |
| Phathom Pharmaceuticals, Inc.Voquezna | $17,851 | $15,03511 claims |
| Braintree Laboratories, Inc.Sutab, Suflave | $32 | $14,05491 claims |
Reading this fairly. The Part D column is what drug plans and patients paid pharmacies — this provider received none of it, and it reflects how many patients they treat and what those drugs cost. Against peers, this provider's reported payments sit in the 90th percentile of 1,885 gastroenterology providers in California.
Other gastroenterology in Anaheim
- Bennett RothLos Angeles$2.8M
- Douglas NguyenMission Viejo$2M
- Sammy SaabLos Angeles$1.9M
- Kenneth ChangNewport Beach$1.3M
- Joo HwangStanford$1M
- Drew SchembreWalnut Creek$659K
- Quan Nhula Jolla$641K
- Sadeea AbbasiLos Angeles$556K
- Ali RezaieWest Hollywood$519K
- Kenneth BinmoellerSan Francisco$507K
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.