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GI Bleeding Evaluation · Cypress & Katy, TX
Blood in Stool Doctor in Cypress & Katy, TX
Blood in the stool can look bright red, dark red, maroon or black, and the color offers clues about where bleeding may be coming from. Some causes are minor, but bleeding that is recurring, unexplained or comes with other symptoms should be evaluated. Muhammad Ali Khan, MD, FACP, FASGE, a board-certified gastroenterologist at United Gastroenterology Associates, evaluates blood in the stool at offices in Cypress and Katy. Call (346) 340-4414.
Appointments: (346) 340-4414
Meet Your Blood in Stool Specialist: Muhammad Ali Khan, MD, FACP, FASGE
BOARD-CERTIFIED Gastroenterologist and Hepatologist
CREDENTIALS AT A GLANCE
Board-Certified
Gastroenterology, hepatology, and internal medicine
Academic Medicine
Former Associate Professor, UT MD Anderson Cancer Center
Published Research
More than 100 peer-reviewed articles in gastroenterology
FACP and FASGE
Fellow, American College of Physicians and American Society for Gastrointestinal Endoscopy
“My gastroenterology & hepatology practice is dedicated to working closely with you to develop a personalized treatment plan that meets your unique needs and preferences.”
Dr. Muhammad Ali Khan, MD, FACP, FASGE
Board-certified gastroenterologist and hepatologist, United Gastroenterology Associates
Blood in the stool is evaluated by Dr. Khan, a gastroenterologist board-certified in gastroenterology, hepatology and internal medicine and a Fellow of the American Society for Gastrointestinal Endoscopy.
Dr. Khan is a former Associate Professor at The University of Texas MD Anderson Cancer Center and has authored more than 100 peer-reviewed publications.
Areas of care
- Bright red and dark blood in stool
- Rectal bleeding and hemorrhoids
- GI bleeding and anemia
- Colonoscopy and polyp removal
- Upper endoscopy (EGD)
What Does Blood in Stool Look Like?
Blood in the stool does not always look the same. Its color depends on where the bleeding starts and how quickly blood moves through the digestive tract. Bright red blood usually comes from the lower colon, rectum or anus. Darker blood often comes from higher in the colon or the small intestine. Black, tarry stool usually points to bleeding in the upper digestive tract.
Seek emergency care right away for:
- Heavy or ongoing rectal bleeding
- Black, tarry stool with weakness, dizziness or fainting
- Vomiting blood or material that looks like coffee grounds
- Confusion or severe, rapidly worsening abdominal pain
Blood in Stool Colors and What They Can Mean
The appearance of stool alone cannot identify the cause, but it helps your gastroenterologist decide where to look first.
| What you see | Possible source | How urgent |
|---|---|---|
| Bright red blood on toilet paper or the outside of stool | Rectum or anus, such as hemorrhoids or an anal fissure | Schedule an evaluation if it recurs or lasts |
| Bright red blood mixed with stool or in the bowl | Lower colon or rectum, such as polyps, colitis or diverticular bleeding | Prompt evaluation |
| Dark red or maroon stool | Higher in the colon or the small intestine | Prompt evaluation; urgent if heavy |
| Black, tarry, sticky stool (melena) | Upper digestive tract, such as an ulcer in the stomach or duodenum | Urgent, especially with weakness or dizziness |
| Dark stool after iron or bismuth medicine | Often a medicine effect rather than bleeding | Ask your doctor if unsure |
What Can Cause Blood in the Stool?
Blood in the stool has many possible causes. Some involve the rectum and anus, while others start higher in the colon, small intestine, stomach or esophagus. Common causes include hemorrhoids, anal fissures, inflammatory bowel disease, diverticular bleeding, colon polyps, ulcers and infections. Colorectal cancer is a less common but important cause.
The presence of blood does not identify the cause by itself, which is why recurring or unexplained bleeding should be evaluated. If your main symptom is bleeding during bowel movements, also see rectal bleeding.
Possible causes
- Hemorrhoids
- Anal fissures
- Inflammatory bowel disease
- Diverticular bleeding
- Colon polyps
- Stomach or duodenal ulcers
- Infections or inflammation
- Colorectal cancer
This is not a complete list. Only an evaluation can identify the source.
When Should You See a Doctor for Blood in Stool?
A single streak of bright red blood after a hard bowel movement that does not return may not need urgent care, but you should still mention it to your doctor. Make an appointment with a gastroenterologist if bleeding happens more than once, keeps returning, or comes with other symptoms.
Adults 45 and older, and anyone with a family history of colorectal cancer or polyps, should be especially careful not to ignore bleeding. A gastroenterologist can review your symptoms, medicines and risk factors and decide whether testing is needed.
Schedule a GI evaluation for
- Blood in stool more than once
- Blood mixed with stool
- A change in bowel habits
- Persistent diarrhea or constipation
- Abdominal pain or cramping
- Unexplained weight loss
- Fatigue, weakness or anemia
Severe bleeding or black, tarry stool needs emergency care.
Blood in Stool With Other Symptoms
The symptoms that come with bleeding help narrow the possible causes.
| Combination | What it may suggest | Learn more |
|---|---|---|
| With abdominal pain | Inflammation, infection, diverticular disease or other causes; severe or sudden pain needs urgent care | Abdominal pain |
| With diarrhea | Inflammation or infection, including colitis | Chronic diarrhea |
| With constipation or straining | Hemorrhoids or an anal fissure, though bleeding should not be assumed to be from constipation | Constipation |
| With fatigue or anemia | Slow, ongoing blood loss that may not be visible | Anemia and GI bleeding |
| With a change in bowel habits | A reason to consider colonoscopy, especially at 45 or older | Changes in bowel habits |
How a Gastroenterologist Evaluates Blood in Stool
Evaluation starts with the details of your symptoms. Testing is chosen based on what is most likely.
Symptom history
When the bleeding started, how often it happens, its color, whether it is mixed with stool, and any pain, diarrhea, constipation or weight change.
Medicines and history
Blood thinners, aspirin, NSAIDs, iron and supplements, plus earlier GI conditions, procedures and family history of colorectal cancer.
Examination
A physical examination, which may include a rectal examination, to look for a source such as hemorrhoids or a fissure.
Lab tests
Blood tests can check for anemia or other clues when appropriate.
Endoscopic testing
Colonoscopy or upper endoscopy when needed to find and often treat the source of bleeding.
Tests That May Be Used for Blood in Stool
Not every patient needs the same tests. Your gastroenterologist will explain what is recommended and why.
| Test | What it does | Learn more |
|---|---|---|
| Colonoscopy | Examines the entire colon and rectum; polyps can be removed and bleeding sources treated | Cypress · Katy |
| Upper endoscopy (EGD) | Examines the esophagus, stomach and duodenum when bleeding may start higher up | EGD |
| Flexible sigmoidoscopy | Examines the rectum and lower colon in selected patients | Sigmoidoscopy |
| Blood tests | Check for anemia and other clues | Ordered when appropriate |
Blood in Stool and Colorectal Cancer Screening
Blood in the stool should not automatically be assumed to mean cancer, but unexplained bleeding is one of the symptoms that calls for evaluation rather than routine screening. If you have symptoms, a colonoscopy done to find their cause is a diagnostic test, not a screening test.
Adults at average risk should begin colorectal cancer screening at age 45. Learn more about colorectal cancer screening guidelines and colon cancer screening in Cypress and Katy.
Patient Reviews
These reviews were shared by patients of United Gastroenterology Associates and are published on the practice website.
“Dr. Khan is an exceptionally kind and compassionate physician. He truly listens to his patients and takes the time to explain everything clearly and thoroughly. His treatment plans are straightforward and easy to understand, and he provides a very personalized, attentive level of care. I felt respected, heard, and genuinely cared for throughout my visit.”
Maria Andreina Behrens · Katy
“Dr Kahn and his staff are AWESOME. He is thorough, kind, listens and puts you at ease. The staff are patient and very helpful. I was so afraid of having a colonscopy. Dr Kahn was wonderful. My procedure went so well. It was over and done with in what seemed like a minute! So expect that! Dr Kahn is excellent, I trust him completely. And I recommend him, and his staff.”
Steph Apie · Fulshear
“Dr. Khan is an amazing physician. He is so kind hearted & wants to help you in every way possible. He listens & doesn’t make you feel rushed. I feel so comfortable talking to him about anything. I am so glad to have him as my gastro doctor. His staff is outstanding as well. Shout out to Dr. Khan & his staff.”
Donna LaPlante · Cypress
Blood in Stool FAQs
Answers to common questions about blood in the stool.
What doctor should I see for blood in my stool?
A gastroenterologist specializes in the digestive tract and can evaluate blood in the stool or other signs of gastrointestinal bleeding. At United Gastroenterology Associates, Muhammad Ali Khan, MD, FACP, FASGE, a board-certified gastroenterologist, sees patients at offices in Cypress and Katy. Call (346) 340-4414.
Is bright red blood in the stool always from hemorrhoids?
No. Hemorrhoids and anal fissures are common causes of bright red blood, but polyps, inflammatory bowel disease, diverticular bleeding and colorectal cancer can also cause it. Persistent, recurring or unexplained bleeding should be evaluated rather than assumed to be hemorrhoids.
What does black stool mean?
Black, tarry stool can mean bleeding higher in the digestive tract, such as the stomach or duodenum, and may need urgent evaluation, especially with weakness or dizziness. Iron supplements and bismuth medicines can also turn stool dark or black, but tarry, sticky stool should not be ignored.
Is blood in the stool a sign of cancer?
Blood in the stool has many causes and usually is not cancer. However, colorectal cancer and precancerous polyps can cause bleeding, so unexplained bleeding, especially with a change in bowel habits, weight loss or anemia, should be evaluated.
Will I need a colonoscopy?
Not always. The right test depends on your age, symptoms, how the blood looks and your risk factors. Many patients with blood in the stool do need a colonoscopy to find the source; others may need an upper endoscopy or other testing first.
When is blood in the stool an emergency?
Go to the nearest emergency room or call 911 for heavy or ongoing bleeding, black tarry stools with weakness or dizziness, vomiting blood, fainting, confusion or severe abdominal pain.
Where can I see a blood in stool doctor in Cypress or Katy?
United Gastroenterology Associates has offices at 21216 Northwest Freeway, Suite 640, Cypress, TX 77429, and 23920 Katy Freeway, Suite 555, Katy, TX 77494. Call (346) 340-4414 to schedule.
Blood in Stool Doctor in Cypress and Katy
Patients from Cypress, Katy, Fulshear, Richmond, Rosenberg and the wider Houston area can be evaluated at either office of United Gastroenterology Associates.
United Gastroenterology Associates – Katy
Katy Freeway (I-10) near the Grand Parkway
- Address: 23920 Katy Freeway, Suite 555, Katy, TX 77494
- Phone: (346) 340-4414
- Hours: Monday–Friday, 8:30 AM–5:00 PM (closed 12:00–1:30 PM for lunch; last appointment 4:30 PM)
United Gastroenterology Associates – Cypress
Northwest Freeway (US-290) in Cypress
- Address: 21216 Northwest Freeway, Suite 640, Cypress, TX 77429
- Phone: (346) 340-4414
- Hours: Monday–Friday, 8:30 AM–5:00 PM (closed 12:00–1:30 PM for lunch; last appointment 4:30 PM)
Get Answers About Blood in Your Stool
Recurring or unexplained bleeding deserves a clear answer. Call (346) 340-4414 or request an appointment in Cypress or Katy.
Sources
- National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of GI Bleeding. niddk.nih.gov
- National Institute of Diabetes and Digestive and Kidney Diseases. Colonoscopy. niddk.nih.gov
- U.S. Preventive Services Task Force. Colorectal Cancer: Screening (2021). uspreventiveservicestaskforce.org
This page provides general information and does not replace medical advice. For heavy bleeding or other emergency symptoms, call 911. Last updated October 5, 2026.