Dr. Hiroshi Mashimo

Gastroenterology
Boston, MA
35 years experience male

Locations

Office

My office hours

Thursday: 4:00pm - 9:00pm
Show more

Insurances accepted

VA healthcare

Office

Boston, MA

About

Bio

Internal Medicine, Gastroenterology and Hepatology. Practice in Boston, MA. Expertise with >100 top-tier publications in immunology, molecular biology, stem cells, advanced endoscopic imaging (optical coherence tomography, confocal endomicroscopy, magnet-driven capsule imaging) and ablations (radiofrequency- and cryo-ablations, mucosal resections) for early cancers, motility disorders e.g. gastroesophageal reflux disorder, dysphagia, achalasia, gastroparesis, ileus, constipation/diarrhea, IBS, and bowel control disorders.

Specialties
Doctors may have more than one area of specialty interest. Board certification in a specialty area means the doctor has completed formal training and has practice experience in that specialty, and has passed the certification examination from the corresponding accredited medical specialty board.

Gastroenterology

Internal Medicine

Urgent Care

Licenses

United States: Massachusetts

Languages spoken

German, Japanese

Doctor Q&A

130 Answers
21 Agrees
The number of answers this doctor has agreed with.
A 38-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Discuss w ur doctor: Right pain less likely relieved w bowel movement, but need to consider more urgent entities such as appendicitis, ovarian cyst, kidney stone if lower ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 23-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Possibly: alcohol itself can be toxic to bone marrow (where blood is made), but also can lead to blood loss from ulcers and varices (dilated veins) in the gut, ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 38-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Possible melena?: If in setting of alcohol, NSAID/aspirin use, etc may be higher likelihood that the described stool was melena, often caused by significant bleeding in... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 21-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Followup w ur doctor: generally w/o lesions, biopsies not taken unless symptoms or history (e.g. of ulcer) warrant including ruling out H pylori. however given ur age (e... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 29-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See MD if chronic: many causes chronic diarrhea/bloat- many treatable/reversible so wud seek MD after discontinue milk/milk products, artificial sugar and sodas& caf... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A member asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Depends on cause: Lingering cough could be sign of lung irritation from virus, or even chronic infection by bacteria (bronchitis or pneumonia). These can also lead to a... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 37-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
May be physiological: Belch is triggered by pressure within stomach, and you may be better able to exert belly pressure when not back-constrained. The ? is why you would ne... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 35-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See MD/urgent care: should seek medical attention if persistent and severe, since may be more serious condition - especially if belly is tender. Urine/kidney stone/infect... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 42-year-old member asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See ur doctor: many causes of pain that you describe including those from belly wall (muscle) or organs below. Pain from such organs as uterus, bladder, appendix and... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 36-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Bile: Diarrhea after cholecystectomy is common, and often caused by bile (green). This may even rarely last an year. Avoid milk products, oily foods, caffei... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 41-year-old member asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See ur doctor: "gas pains" can also be symptoms of other treatable causes such as ulcers, poor stomach emptying, hernias, poor biting (ill-fitting dentures or malocc... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 38-year-old member asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See ur doctor: depends on the bowel problem, and its urgency. Urgent /emergent medical care needed for red flags such as dehydration from severe nausea/vomit/diarrhe... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 27-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Possible but seek MD: prolonged xerostomia should warrant MD evaluation - many medications such as for allergies, sleep and anxiety can cause this, but other hormonal/metab... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 18-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See MD: besides pregnancy check, if applicable, see MD if longer than few days and not helped by antacids, as may need workup.Besides infection or inflammatio... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 26-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See your PCP: Rule out pregnancy, if applicable, and seek MD attention esp if chronic, but seek urgent care if "red flags" e.g. bleeding, nausea/vomiting, fever/chi... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 20-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See ur doctor: i'm assuming pregnancy test & urine test (e.g. for infection or trace blood w stones) are negative. unclear what ultrasound looked at - appendix c... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Follow up with MD: generally antibiotics not for cold (viral), but for bacteria that can arise in setting of cold. Mucus production can be in setting of either, but gree... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 40-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See ur doctor: Change in bowel habits common, but shouldn't linger months. Common causes: lactose intolerance (from cow milk and products), alcohol/caffeine, artific... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 81-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Call ur doctor: alendronate can be irritative to the gastrointestinal tract and should call your doctor regarding continuing, or addition of stomach medications empir... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 22-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Possibly: blood after hard BM likely from tear or hemorrhoids, and constipation likely from dehydration with imbibing alcohol. But red flags requiring urgent me... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 38-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
?medicines: Besides foods, the most common reason is medicines that have small capsules within a capsule that enables delivery of the medicine beyond the stomach ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 20-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Would use new: generally good policy not to take expired medications, and I would get fresh antacids, or even try household baking soda if you feel this is from sto... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 53-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Seek MD if thrombose: Hemorrhoids can be felt as lump; may bleed intermittently; seek medical attention if evidence of thrombosis, i.e. clot w tenderness, pain, or even fe... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 28-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Seek medical care: other factors such as family history (of inflammatory conditions and cancer), environmental exposure, and symptoms (associated fevers, diarrhea, const... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 22-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Seek MD for followup: white/pale stool consistent with lack of bile, and may even see oil slick in toilet bowl if diet of hi oil/fat. Blockage can be intermittent, and assu... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 72-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Seek MD attention: The pain could be from number causes but need urgent MD attention if worse pain esp consider: appendicitis, hernias which can get strangulated, or (le... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 38-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Followup w ur doctor: in itself not explain ur symptoms. may need other workup including rule out celiac sprue, pancreatic disease, kidney stones, constipation, etc Need mo... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 34-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Suggest see MD: more info would be needed on medications, underlying conditions e.g. allergies/food intolerances, ethnicity, etc. Be sure checked for pregnancy if ap... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 32-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Frd need MD followup: depends on cause of unconsciousness e.g. seizure, diabetes, stroke, vasovagal, drugs, alcohol, etc. - many such causes can have stomach pain afterward... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 18-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
If continued see doc: viral gut infections most common and generally goes away in a week but gut reactions can also be from other issues like pregnancy, bladder infection... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 18-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Yes: can get pregnant at any time since period may not be unreliable marker of ovulation timing esp if irregular or varied in flow/duration. do check urine... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 29-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Dep. severity; fluid: matter of symptoms/severity - not just stool frequency, but also straining, incomplete evacuation, pain/cramp. Severe complications can incl bleeding ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 25-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Consider GI: if omeprazole or other "proton pump inhibitor" drug class not work, talk to GI doc, rv proper use (take first thing a.m. followed by decent meal 30-60... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 27-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Likely mixed blood: Likely mixed blood from hemorrhoids, but be sure you have seen Gastroenterologist to rule out other inflammatory or infectious causes of blood and hem... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 30-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Would need more info: I assume ur symptom largely pain/cramps RELIEVED w bowel movement. Assume w/u during hospitalizations has been negative in past. Happy to rv details o... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 22-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Correct - insurance?: Prilosec (omeprazole:10,20mg) is available generic, and likely better covered by US insurance formularies. Nexium (esomeprazole: 40mg i.e. double) is ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 23-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Safe but see MD: depends on why you were taking probiotics. If recommended by MD, would continue until followup visit. Alone, is not major cause of changing blood pres... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 35-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Beats per minute: BPM=beats per minute of your heart rate. Many things can increase such as exercise, fever, anxiety, dehydration, certain medicines, or even underlying... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 33-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Seek MD: chronic nausea/vomit would require workup but more info needed eg drugs (esp opioids, psych meds), recreational drugs, other medical probs(eg diabetes... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See MD if repeated: many entities can cause - commonly constipation (mucous flow around blockage), but also others like infection, inflammation, gut food allergies, tumor... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 52-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Depends type2 is les: depends on what is meant by "advanced"; natural progression still poorly understood. But success of therapy differs: Type2 easiest to treat w nearly 1... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A member asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See dermatologist: if u have not done so already, be sure to see a dermatologist. a true cyst has a “skin” encasing the cyst which needs to be carefully removed to avoid... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 33-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
See your doctor: this may indeed be from prednisone, or from some underlying disorder for which you are taking prednisone, or even some infection such as viral (since ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 25-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Not optimal: taking with or after meal is not optimal since acid will be secreted before drug has chance to get into blood stream. Ideally should be taken first th... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 45-year-old member asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Many causes- see MD: there are many potential causes for your symptoms. As common as they may be, may warrant evaluation by Gastroenterology specialist, esp if severe, chr... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 19-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Review w ur doctor: Especially if more frequent or severe, would seek specialty care such as gastroenterologist who can rule out common cases such as food allergies (esp... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 38-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Dep cause/severity: if unable to keep fluids down, and evidence of dehydration, weakness, blood, or fevers, suggest urgent attention by MD - need to r/o other emergent is... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 43-year-old female asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Seek MD attention: causes of left lower belly pain include commonly kidney stones, ovarian cysts, appendicitis, infections, inguinal/femoral hernia, muscle strain, and ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 51-year-old male asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Yes: cecal ulcer is ulcer in the cecum of your colon, where the small intestine and appendix attach. NSAIDs are the most common cause of isolated ulcer in ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A member asked:
Dr. Hiroshi Mashimo
Gastroenterology 35 years experience
Discuss w ur doctor: Pain at incision after surgery common, but relation to eating more concerning. Discuss w your doctor underlying cause. Avoid less digestible or fermen... Read More
Created for people with ongoing healthcare needs but benefits everyone.

Testimonials
Recommendations and Thank you notes are endorsements given from patients or other doctors.

3
Recommendations
113
Thank you notes
Nov 15, 2015
Dr. Mashimo is a worldwide expert in problems related to GI motility. And he's a really nice guy.
HealthTap member
Mar 31, 2015
Dr. Mashimo is an amazing doctor! #nationaldoctorsday2015 #virtualflower1
HealthTap member
Mar 31, 2015
Dr. Mashimo is an amazing doctor! #nationaldoctorsday2015 #virtualflower1
HealthTap member
This was very helpful. Thanks! Thank you so much! He is getting worse so your answer will help me convince him to get to doctor asap. Thank you again!!
HealthTap member
Thank you, your answer was very helpful! Thanks doc atleast I know there hope and can still have caffeine
HealthTap member
Your answer was very helpful, thanks! Thank you Doctor. Blessings your way.

Education & Training

Medical/Graduate school

Albert Einstein College of Medicine of Yeshiva University, NY
MD

Residency

MASSACHUSETTS GENERAL HOSPITAL

Awards

Top Gastroenterologist , Second Place, Massachusetts - Summer
2013
Most Influential Doctor, Massachusetts - Winter
2015
Thought Leader, Massachusetts - Winter
2015

Affiliations

American Gastroenterlogy Association
American Motility Society
Alpha Omega Alpha Honor Medical Society
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