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Patient Instructions · United Gastroenterology Associates
Colonoscopy Prep Instructions by Prep Type
Choose the bowel prep your doctor prescribed to open its step-by-step instructions. Start with the General Colonoscopy Instructions, which cover medicines, diet, your driver and arrival, then follow the page for your specific prep. These instructions are for patients scheduled with Muhammad Ali Khan, MD, FACP, FASGE, at United Gastroenterology Associates in Katy and Cypress. Questions about your prep? Call (346) 340-4414.
Prep questions: (346) 340-4414
Find Your Colonoscopy Prep Instructions
Your bowel prep is the laxative that cleans out your colon so Dr. Khan can see the lining clearly. Each prep is taken differently, so use the instructions for the exact prep on your prescription. If you are not sure which prep you were prescribed, check the pharmacy label or call the office.
Important
Follow the instructions given to you by your doctor. Do not stop, start or change any medicine unless Dr. Khan's office or your prescribing doctor tells you to. If the instructions you received differ from this page, follow the instructions you received.
Choose Your Prep Type
Colonoscopy Prep Types at a Glance
Read the General Colonoscopy Instructions first, then the instructions for your prep.
| Prep | Form | Instructions |
|---|---|---|
| General instructions | All patients | General colonoscopy instructions |
| Clenpiq | Liquid | Clenpiq prep instructions |
| CoLyte | Liquid | CoLyte prep instructions |
| MoviPrep | Liquid | MoviPrep prep instructions |
| Plenvu | Liquid | Plenvu prep instructions |
| Suflave | Liquid | Suflave prep instructions |
| Sutab | Tablets | Sutab prep instructions |
| Suprep | Liquid | Suprep prep instructions |
Preparing for a different procedure? See all procedure preparation instructions, including upper endoscopy, flexible sigmoidoscopy and ERCP.
Key Rules From the General Colonoscopy Instructions
These points summarize the practice's general colonoscopy instructions. Read the full general colonoscopy instructions for details, and follow any personal instructions the office gives you.
- Driver: an adult must drive you home and stay at the center during your procedure.
- Blood thinners: ask the office for guidance before your procedure. Do not stop them on your own.
- GLP-1 medicines: tell the office if you take one. The instructions give separate timing for weekly and daily GLP-1 medicines.
- Iron, diet pills and herbal medicines: the instructions ask you to stop these 7 days before.
- Alcohol: avoid for 24 hours before and after your colonoscopy.
- Before arrival: nothing by mouth starting 3 hours before you arrive, except approved medicines with up to 2 tablespoons of water.
- Rescheduling: call at least 3 to 4 days ahead.
Tell the office before your prep if you
- Take a blood thinner or aspirin
- Have diabetes or take insulin
- Take a GLP-1 medicine
- Have kidney or heart disease
- Are pregnant or may be pregnant
These conditions can change how you prepare. The office will give you personal instructions.
Colonoscopy Prep Timeline
A general outline. Your prep page gives the exact timing and doses for your prep.
About 7 days before
Read your instructions, pick up your prep, arrange your driver, and call the office about blood thinners, diabetes, GLP-1 medicines, iron or supplements.
A few days before
Follow any low-fiber diet instructions on your prep page. See what you can eat before a colonoscopy.
The day before
Switch to clear liquids as directed and take the first part of your prep at the time shown in your instructions.
The day of your colonoscopy
Take the second part of your prep as directed. Take nothing by mouth from 3 hours before arrival, except approved medicines.
After your colonoscopy
Your driver takes you home. Rest, avoid alcohol for 24 hours, and follow the discharge instructions you receive.
How to Tell if Your Prep Is Working
A good prep matters. If the colon is not clean, small polyps can be missed and the colonoscopy may need to be repeated. By the end of your prep, your bowel movements should be liquid, clear or light yellow, and free of solid pieces.
Splitting the prep into two doses, with the second dose on the morning of your procedure, helps most people get a cleaner colon. Your prep page tells you exactly when to take each dose.
Call the office if
You vomit your prep, cannot finish it, still have brown or solid stool after finishing, or feel dizzy, faint or very weak. For severe abdominal pain or symptoms of an emergency, call 911.
Questions About Your Prep?
If you are unsure about your prep, your medicines or your arrival time, call the office before you start.
Learn More Before Your Colonoscopy
For a plain-language overview of the days leading up to your exam, read how to prepare for a colonoscopy. To understand the procedure itself, see colonoscopy services and what a colonoscopy can detect. If you are paying without insurance, see self-pay colonoscopy.
Colonoscopy Prep FAQs
Answers to common questions from patients preparing for a colonoscopy.
Which colonoscopy prep instructions should I follow?
Follow the instructions for the prep your doctor prescribed. At United Gastroenterology Associates, start with the General Colonoscopy Instructions, then open the page for your specific prep: Clenpiq, CoLyte, MoviPrep, Plenvu, Suflave, Sutab or Suprep. If anything in your printed instructions differs from this page, follow the instructions from your doctor and call the office with questions.
Do I need to stop my medicines before a colonoscopy?
Do not stop or change any medicine on your own. Tell the office about blood thinners, diabetes medicines, GLP-1 medicines for diabetes or weight loss, iron and supplements. The practice will tell you what to hold and when, and some changes need to be coordinated with the doctor who prescribes the medicine.
How do I know if my colonoscopy prep is working?
By the end of your prep, your bowel movements should be liquid, clear or light yellow, and free of solid pieces, similar to urine. If your stool is still brown or contains solid material after you finish the prep, call the office before your procedure.
Can I drive myself home after a colonoscopy?
No. You receive sedation, so an adult driver must take you home. The practice's instructions ask that your driver stay at the procedure center during your colonoscopy.
When do I have to stop eating and drinking before a colonoscopy?
Follow the timing in your prep instructions. The practice's general instructions say to take nothing by mouth starting 3 hours before your arrival time, except usual medicines you have been told to take with up to 2 tablespoons of water.
What if I need to reschedule my colonoscopy?
Call the office as early as possible. The practice asks for at least 3 to 4 days' notice to reschedule.
Can I drink alcohol before or after a colonoscopy?
No. The practice's instructions say to avoid alcohol for 24 hours before and 24 hours after your procedure.
United Gastroenterology Associates Offices
Questions about your prep or appointment can be answered by either office. Your arrival location and time are in your appointment instructions.
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)
Ready for Your Colonoscopy Prep?
Start with the General Colonoscopy Instructions, then follow the page for your prep. Call (346) 340-4414 with any questions.
Sources
- American Society for Gastrointestinal Endoscopy. Understanding Bowel Preparation. asge.org
- National Institute of Diabetes and Digestive and Kidney Diseases. Colonoscopy. niddk.nih.gov
This page summarizes general preparation information for patients of United Gastroenterology Associates. It does not replace the personal instructions you receive from your doctor. Do not change any medicine without medical guidance. For a medical emergency, call 911. Last updated October 5, 2026.