Dr. Howard B. Hamat, MD

Dr. Howard B. Hamat, Gastroenterologist and Hepatology Specialist

Dr. Howard B. Hamat is a board-certified gastroenterologist providing diagnostic, preventive, and procedural care for adults with conditions affecting the digestive tract, liver, gallbladder, bile ducts, and pancreas.

His clinical background includes advanced training in inflammatory bowel disease and therapeutic biliary endoscopy. He evaluates common digestive symptoms, manages long-term gastrointestinal and liver conditions, and performs procedures such as colonoscopy and upper gastrointestinal endoscopy.

Patients comparing digestive health specialists can also read about Dr. Ryan R. Barrientos and his gastroenterology care.

Doctor Information

Name: Dr. Howard B. Hamat, MD
Specialty: Gastroenterology
Additional Clinical Focus: Hepatology and Internal Medicine
Board Certification: Gastroenterology
Medical School: University of Toronto Faculty of Medicine
Medical Degree Completed: 1990
Gastroenterology Fellowship: University of Toronto
Fellowship Completed: 1995
Advanced Training: Inflammatory Bowel Disease and Therapeutic Biliary Endoscopy
Practice: Digestive and Liver Disease Consultants, PA
Practice Since: 1997
Primary Practice Area: Greater Houston, Humble, and The Woodlands region
Languages Spoken: English and Spanish
NPI Number: 1376537605
Accepting New Patients: Current availability should be confirmed directly with the practice

About Dr. Howard B. Hamat

Dr. Hamat earned his medical degree from the University of Toronto Faculty of Medicine in 1990. He remained at the University of Toronto for specialist medical training and completed his fellowship in gastroenterology in 1995.

After completing his general gastroenterology fellowship, he pursued an additional year of advanced training in inflammatory bowel disease and therapeutic biliary endoscopy. This training provided focused experience in the management of Crohn’s disease and ulcerative colitis, as well as endoscopic procedures used to diagnose and treat problems involving the bile ducts and pancreas.

Dr. Hamat moved to Houston and joined Digestive and Liver Disease Consultants in 1997. His work covers both outpatient digestive care and endoscopic procedures for patients with gastrointestinal, liver, pancreatic, and biliary conditions.

His training in internal medicine also helps him consider how digestive symptoms may interact with diabetes, cardiovascular disease, kidney function, medication use, nutrition, and other health concerns.

Gastroenterology Care

Gastroenterology focuses on the organs responsible for digestion, nutrient absorption, and waste removal. These include the esophagus, stomach, small intestine, colon, rectum, liver, gallbladder, bile ducts, and pancreas.

Dr. Hamat may evaluate and manage conditions such as:

• Gastroesophageal reflux disease
• Persistent heartburn
• Difficulty swallowing
• Gastritis
• Peptic ulcer disease
• Irritable bowel syndrome
• Crohn’s disease
• Ulcerative colitis
• Diverticular disease
• Chronic constipation
• Persistent diarrhea
• Gastrointestinal bleeding
• Colon polyps
• Celiac disease
• Fatty liver disease
• Viral hepatitis
• Cirrhosis
• Gallbladder and bile duct disorders
• Pancreatic conditions
• Unexplained abdominal pain

Many digestive symptoms have several possible causes. A proper assessment may include a medical history, physical examination, blood testing, stool studies, imaging, or an endoscopic procedure.

Abdominal Pain Evaluation

Abdominal pain can arise from the stomach, intestines, liver, gallbladder, pancreas, abdominal wall, urinary system, or another medical condition.

During an evaluation, Dr. Hamat may ask:

• Where the pain is located
• When the discomfort began
• Whether it is constant or intermittent
• Whether meals affect the pain
• Whether bowel habits have changed
• Whether nausea or vomiting occurs
• Whether there is fever
• Whether weight has changed unexpectedly
• Which medications are being used
• Whether previous abdominal surgery was performed

Testing may include laboratory work, ultrasound, CT imaging, upper endoscopy, colonoscopy, or another procedure based on the symptom pattern.

Treatment is selected according to the identified cause rather than abdominal pain alone.

Acid Reflux and GERD

Gastroesophageal reflux disease occurs when stomach contents repeatedly move upward into the esophagus. It may cause heartburn, a sour taste, chest discomfort, coughing, hoarseness, or trouble swallowing.

Dr. Hamat may evaluate patients experiencing:

• Frequent heartburn
• Acid regurgitation
• Upper abdominal discomfort
• Painful swallowing
• Food becoming stuck
• Chronic throat irritation
• Nighttime coughing
• Symptoms that continue despite medication
• Possible Barrett’s esophagus

Treatment may involve changes to meal timing, medication, weight-related health support, and reduction of personal symptom triggers.

Upper endoscopy may be recommended when symptoms are persistent, swallowing becomes difficult, gastrointestinal bleeding is suspected, or treatment does not provide enough improvement.

Upper Gastrointestinal Endoscopy

Upper gastrointestinal endoscopy, also known as EGD, allows the physician to examine the esophagus, stomach, and first part of the small intestine.

The procedure may help investigate:

• Persistent reflux
• Difficulty swallowing
• Upper abdominal pain
• Nausea or vomiting
• Gastrointestinal bleeding
• Unexplained anemia
• Peptic ulcers
• Abnormal imaging findings
• Inflammation
• Unexplained weight loss

A flexible instrument containing a camera is passed through the mouth while the patient receives appropriate sedation or medication.

Small tissue samples may be collected during the procedure. Narrowed areas may also be treated when medically suitable.

Patients receive instructions about fasting, medication, transportation, and recovery before the procedure.

Colonoscopy and Colorectal Cancer Screening

Colonoscopy allows the gastroenterologist to examine the colon and rectum. It may be used for preventive colorectal cancer screening or to investigate digestive symptoms.

Reasons for colonoscopy may include:

• Age-appropriate colorectal cancer screening
• Family history of colorectal cancer
• Previous colon polyps
• Blood in the stool
• Unexplained anemia
• Persistent diarrhea
• Continuing constipation
• Changes in bowel habits
• Abnormal stool-test results
• Inflammatory bowel disease monitoring
• Unexplained abdominal discomfort

Polyps can often be removed during the same procedure. Removed tissue is normally sent to a laboratory for examination.

The recommended timing of future colonoscopies depends on previous findings, polyp type, family history, bowel preparation quality, and individual risk factors.

Patients looking for another gastroenterology specialist can review Dr. Peter E. Bloom’s digestive health profile.

Colon Polyps

Colon polyps are growths that develop on the inner lining of the colon. Many polyps are harmless, but some types can gradually become cancerous.

Most polyps do not cause noticeable symptoms. This is one reason preventive screening is important for eligible patients.

Management may involve:

• Polyp removal during colonoscopy
• Laboratory examination of removed tissue
• Follow-up colonoscopy
• Review of personal and family history
• Additional treatment for large or complex growths

The timing of follow-up depends on the number, size, location, and laboratory findings of the polyps.

Colonoscopy Preparation

The colon must be properly cleaned before colonoscopy so the physician can examine its lining clearly.

Preparation may include:

• Following temporary dietary restrictions
• Changing to approved clear liquids
• Taking prescribed bowel-cleansing medicine
• Drinking enough permitted fluids
• Following fasting instructions
• Discussing blood-thinning medicines
• Adjusting selected diabetes medicines
• Arranging transportation after sedation

Patients should tell the medical team about kidney disease, heart conditions, diabetes, medication allergies, constipation, or difficulty completing previous bowel preparations.

Following the instructions carefully reduces the chance of missed findings or a repeated procedure.

Inflammatory Bowel Disease

Inflammatory bowel disease includes Crohn’s disease and ulcerative colitis. These are long-term conditions that cause inflammation in the digestive tract.

Dr. Hamat completed advanced training in inflammatory bowel disease and may evaluate symptoms such as:

• Persistent diarrhea
• Abdominal cramping
• Blood in the stool
• Bowel urgency
• Unintended weight loss
• Reduced appetite
• Tiredness
• Anemia
• Fever during disease flares
• Joint, eye, or skin symptoms

Diagnosis may involve blood tests, stool testing, colonoscopy, tissue samples, and imaging of the small intestine.

Treatment may include anti-inflammatory medicine, immune-modifying treatment, biologic therapy, nutrition support, and continuing monitoring.

The treatment plan depends on the type of inflammatory bowel disease, location of inflammation, severity, previous medication response, and presence of complications.

Crohn’s Disease Care

Crohn’s disease can affect any part of the digestive tract, although it commonly involves the small intestine or colon.

Symptoms may include:

• Abdominal pain
• Chronic diarrhea
• Weight loss
• Reduced appetite
• Rectal bleeding
• Fatigue
• Fever
• Mouth sores
• Symptoms outside the digestive system

Crohn’s disease may cause narrowing, abnormal connections between organs, abscesses, or nutritional problems in some patients.

Dr. Hamat may use laboratory testing, colonoscopy, imaging, and medication monitoring to assess disease activity.

Treatment aims to control inflammation, reduce symptoms, support healing, and prevent complications. Some patients may require surgical consultation when medication does not adequately control a structural complication.

Ulcerative Colitis Care

Ulcerative colitis causes continuing inflammation of the inner lining of the colon and rectum.

Possible symptoms include:

• Bloody diarrhea
• Bowel urgency
• Abdominal cramping
• Frequent bowel movements
• Rectal discomfort
• Anemia
• Tiredness
• Weight loss during severe disease

Treatment depends on how much of the colon is affected and how active the inflammation has become.

Care may include oral medicine, rectal treatment, immune-targeting therapy, laboratory monitoring, and periodic colonoscopy.

Long-term colon inflammation can increase colorectal cancer risk, so patients may need a specialised surveillance schedule.

Irritable Bowel Syndrome

Irritable bowel syndrome can cause abdominal pain, bloating, constipation, diarrhea, or alternating bowel habits.

Unlike inflammatory bowel disease, irritable bowel syndrome does not cause the same visible inflammation or tissue injury.

An evaluation may include:

• Review of bowel patterns
• Assessment of food-related symptoms
• Medication review
• Medical and family history
• Blood or stool testing
• Identification of warning signs
• Previous endoscopy or imaging results

Treatment may involve dietary changes, fiber adjustment, medication, sleep support, and management of individual triggers.

Additional testing may be required when bleeding, anemia, fever, weight loss, or a major change in symptoms occurs.

Celiac Disease

Celiac disease is an immune reaction to gluten that can damage the small intestine.

Possible symptoms include:

• Diarrhea
• Abdominal bloating
• Constipation
• Weight loss
• Iron-deficiency anemia
• Tiredness
• Nutritional deficiencies
• Bone weakness
• Skin symptoms

Testing may include specific blood tests and small-intestinal biopsies collected during upper endoscopy.

Patients should generally avoid beginning a gluten-free diet before testing unless advised by a healthcare professional, because removing gluten early may affect diagnostic results.

Confirmed celiac disease is managed through strict avoidance of gluten and monitoring for nutritional deficiencies or related conditions.

Diverticular Disease

Diverticula are small pouches that can develop in the wall of the colon. The presence of these pouches is called diverticulosis.

When a pouch becomes inflamed or infected, the condition is known as diverticulitis.

Symptoms may include:

• Lower abdominal pain
• Fever
• Changes in bowel habits
• Nausea
• Abdominal tenderness
• Bloating

Evaluation may involve blood tests and CT imaging. Treatment depends on symptom severity and whether complications are present.

Some patients can be treated with medication, temporary dietary adjustments, and monitoring. Hospital care or surgery may be required when an abscess, perforation, obstruction, or repeated severe inflammation develops.

Gastrointestinal Bleeding

Bleeding within the digestive tract may appear as red blood, dark stool, vomiting of blood, or anemia found during laboratory testing.

Possible causes include:

• Peptic ulcers
• Esophageal inflammation
• Diverticular disease
• Hemorrhoids
• Colon polyps
• Inflammatory bowel disease
• Blood vessel abnormalities
• Medication-related irritation
• Gastrointestinal growths

Dr. Hamat may use upper endoscopy, colonoscopy, capsule testing, imaging, or laboratory studies to identify the source.

Some bleeding sites can be treated during an endoscopic procedure. Treatment depends on the cause, severity, medication use, and the patient’s general health.

Liver Disease Care

The liver processes nutrients, supports digestion, produces important proteins, and helps remove waste products from the body.

Dr. Hamat may evaluate and manage:

• Abnormal liver blood tests
• Fatty liver disease
• Metabolic liver disease
• Viral hepatitis
• Alcohol-related liver injury
• Cirrhosis
• Autoimmune liver conditions
• Medication-related liver damage
• Bile duct disorders
• Liver lesions identified through imaging

An evaluation may include blood tests, ultrasound, CT or MRI imaging, fibrosis assessment, and review of medication, alcohol exposure, weight-related risks, and family history.

Treatment depends on the cause and degree of liver injury.

Patients seeking another gastroenterologist with liver-care experience can read about Dr. Surendar Baradhi’s gastroenterology and hepatology services.

Fatty Liver Disease

Fatty liver disease occurs when excess fat collects within liver cells. It is often associated with insulin resistance, type 2 diabetes, high cholesterol, high triglycerides, or other metabolic risk factors.

Many people have no obvious symptoms. The condition may be found after abnormal blood tests or imaging performed for another reason.

Evaluation may include:

• Liver enzyme testing
• Metabolic health review
• Ultrasound or other imaging
• Fibrosis assessment
• Medication review
• Testing for other liver conditions

Care focuses on reducing liver injury and managing related health risks. Follow-up is particularly important when testing suggests inflammation or scarring.

Cirrhosis Management

Cirrhosis develops when long-term liver injury causes extensive scar tissue. Early disease may cause few symptoms, while advanced cirrhosis can affect fluid balance, bleeding risk, digestion, and mental clarity.

Management may involve:

• Laboratory monitoring
• Liver imaging
• Screening for enlarged veins
• Monitoring for liver cancer
• Fluid and swelling management
• Nutrition guidance
• Treatment of the underlying cause
• Medication review
• Referral for transplant assessment when appropriate

Patients with cirrhosis should discuss all prescription medicines, non-prescription products, vitamins, and supplements with their healthcare team.

Bile Duct and Gallbladder Conditions

The gallbladder stores bile, while the bile ducts carry bile from the liver toward the small intestine.

Dr. Hamat may assess:

• Bile duct stones
• Biliary obstruction
• Bile duct narrowing
• Gallstone-related complications
• Abnormal liver tests
• Yellowing of the skin or eyes
• Upper-right abdominal pain
• Biliary infection
• Abnormal bile duct imaging

Testing may include ultrasound, CT, MRI-based bile duct imaging, or an endoscopic procedure.

Some patients require gallbladder surgery, while others need endoscopic treatment to remove a bile duct stone or improve drainage.

Therapeutic Biliary Endoscopy

Dr. Hamat completed advanced training in therapeutic biliary endoscopy. This field uses endoscopic techniques to diagnose and treat selected conditions involving the bile ducts and pancreatic ducts.

A procedure called ERCP may be used to:

• Remove bile duct stones
• Treat selected duct blockages
• Place a temporary stent
• Open a narrowed duct
• Collect tissue samples
• Treat certain bile leaks
• Assess abnormal duct findings

ERCP is generally used when treatment or important diagnostic information is expected. It is not the first test for every gallbladder or pancreatic symptom.

Pancreatic Conditions

The pancreas produces digestive enzymes and hormones involved in controlling blood sugar.

Dr. Hamat may evaluate:

• Acute pancreatitis
• Chronic pancreatitis
• Pancreatic cysts
• Abnormal pancreatic imaging
• Pancreatic duct conditions
• Digestive enzyme insufficiency
• Selected pancreatic growths

Testing may involve blood work, CT imaging, MRI, endoscopic ultrasound, or ERCP.

Treatment depends on the diagnosis and may involve medication, nutrition support, endoscopic procedures, surgery, or coordination with other specialists.

Digestive Diagnostic Testing

Depending on the patient’s symptoms, Dr. Hamat may recommend:

• Blood testing
• Stool studies
• Abdominal ultrasound
• CT or MRI imaging
• Upper gastrointestinal endoscopy
• Colonoscopy
• Tissue biopsy
• Capsule endoscopy
• ERCP
• Liver fibrosis assessment
• Breath testing

Not every patient needs every test. Investigations are selected according to the symptom pattern, medical history, physical findings, and suspected condition.

Preparing for a Gastroenterology Appointment

Patients can prepare by bringing:

• A current medication list
• Previous colonoscopy reports
• Earlier endoscopy reports
• Laboratory results
• Abdominal imaging
• Hospital discharge records
• A list of medication allergies
• Details about bowel habits
• Family history of digestive disease
• Notes about current symptoms
• Questions about testing or treatment

It may help to record:

• When symptoms occur
• Which foods appear to affect symptoms
• Changes in bowel frequency
• Stool appearance
• Episodes of bleeding
• Fever or vomiting
• Unexplained changes in weight
• Treatments already attempted

Patients should also mention blood thinners, diabetes medicine, supplements, and previous reactions to sedation.

Patient-Focused Digestive and Liver Care

Dr. Hamat provides care for both common digestive symptoms and complex gastrointestinal or liver conditions. His services include digestive health consultations, preventive colonoscopy, upper endoscopy, inflammatory bowel disease management, liver assessment, and therapeutic biliary procedures.

His advanced training supports care for patients with Crohn’s disease, ulcerative colitis, bile duct disorders, and other conditions that may require detailed endoscopic evaluation.

Treatment recommendations are based on symptoms, medical history, test results, existing conditions, and response to earlier care.

Patients should confirm current appointment availability, accepted insurance plans, procedure locations, preparation requirements, and referral policies directly with the practice.

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Meta Description: Meet Dr. Howard B. Hamat, a board-certified gastroenterologist providing colonoscopy, endoscopy, inflammatory bowel, liver, and biliary care.