This is a quick guide for bowel prep before and during your radiation therapy. It’s meant for people who are getting one of these types of radiation therapy:
- Intensity-modulated radiation therapy (IMRT) to your prostate
- Radiation therapy after prostate surgery (post-prostatectomy radiation therapy)
Read About Intensity-Modulated Radiation Therapy (IMRT) to Your Prostate or About Radiation Therapy After Prostate Surgery for full instructions.
3 days before your simulation
- Start taking 2 (125 mg) simethicone (Gas-X®) tablets after breakfast and after dinner. Take them every day.
- Start taking 1 (5 mg) bisacodyl (Dulcolax®) tablet at night. Take it every night.
It’s OK to stop taking the simethicone and bisacodyl tablets after your simulation while your care team plans your treatments.
3 days before your first radiation treatment
- Restart taking 2 (125 mg) simethicone (Gas-X) tablets after breakfast and after dinner every day.
- Restart taking 1 (5 mg) bisacodyl (Dulcolax) tablet every night.
During your radiation therapy
Try to poop within 1 hour before your radiation treatment appointments.
Tell your care team if you start to have diarrhea. We can help you adjust your bisacodyl dose.
Tell your care team if you’re following these instructions but still can’t poop before each treatment. We can adjust your bowel prep to find something that works better for you.
Helpful reminders
To reduce gas and bloating:
- Eat slowly, chew your food well, and avoid using drinking straws or drinking from bottles and cans. This will help you avoid swallowing air.
- Avoid carbonated drinks, such as seltzer, soda, and beer.
- Limit foods and drinks that produce gas when they’re digested. Examples include broccoli, Brussels sprouts, cabbage, cauliflower, kale, onions, garlic, dried fruits, and milk and dairy if you’re lactose intolerant. Read the section “Diet guidelines to limit bloating” in About Intensity-Modulated Radiation Therapy (IMRT) to Your Prostate or About Radiation Therapy After Prostate Surgery for the full list.
- Choose cooked vegetables instead of raw vegetables.
To help fill your bladder:
- It’s important to stay well hydrated. Most people need to have a comfortably full bladder for their simulation and radiation treatments.
- We suggest you drink about 64 ounces (8 cups) of water each day leading up to your appointments, unless another healthcare provider has told you to limit the amount you drink.
- Your radiation therapist will give you more instructions during your simulation appointment.
