Tube Feeding: How to Bolus/Syringe Feed

Amy Long Carrera, MS, RD, CNSC, CWCMS
Registered Dietitian Nutritionist | Shield HealthCare
09/16/15  1:56 PM PST
Bolus feeding

Bolus feeding is a type of feeding method using a syringe to deliver formula through your feeding tube. It may also be called syringe or gravity feeding because holding up the syringe allows formula to flow down using gravity. Most people take a bolus or a “meal” of formula about every three hours or so. This allows you to have more freedom in between feedings. A feeding will usually take up to 20 minutes.

To bolus feed, you will need:

  • 60-milliliter (mL) catheter tip or oral syringe
  • Cup of room-temperature water
  • Formula

How to Bolus/Syringe Feed:

  1. Wash your hands.
  2. If you have a low profile feeding tube, prime the extension tubing to remove any air before attaching it to the feeding tube. Priming the tubing helps prevent air from entering your stomach and causing discomfort.
    1. Clamp the extension set.
      1. Remove the plunger from the syringe and attach the syringe to the extension tubing.
  3. Pour about 15 mL of formula into the syringe.
    1. Unclamp the extension set, allowing the formula to flow just to the end of the tubing and clamp the extension set.
    2. Attach the extension set to the feeding tube.
  4. If you have a regular gastrostomy tube, flush your tube with water.
    1. Remove the plunger from the syringe.
    2. Attach the syringe to your feeding tube
    3. Pour 10-15 mL of water into the syringe and let it flow through your tube.
  5. Clean off the outside of your formula container with a clean towel and open it.
  6. Hold up the tube and syringe with one hand.
  7. Slowly pour formula into the syringe with your other hand. Allow it to flow by gravity into your stomach. It should take around 15 minutes to deliver 8 ounces of formula.
  8. Feed more slowly or more quickly depending on your tolerance.
    • You can make the formula flow faster by raising the syringe higher in relation to your stomach or by using the plunger push the formula through.
    • You can make the formula flow more slowly by lowering the syringe in relation to your stomach or by taking only ¼ or ½ of the can at a time with a minute or two in between.
  9. Flush your feeding tube with the amount of water recommended.
  10. Close the feeding port and disconnect the extension tubing (if applicable).
  11. Wash your hands.
  12. Wash and air-dry all equipment and supplies.
  13. Refrigerate any leftover formula and use within 24 hours.


Bolus Feeding Tips:

  • To prevent infection, always wash your hands before handling the feeding tube,  supplies and your skin.
  • You should have better tolerance if you are sitting up during your feedings and for at least 30 minutes afterward.
  • Cold formula may upset your stomach, so take it out of the fridge a few minutes before a feeding.
  • You may need to slow down the formula if you start to feel nauseous or too full during the feeding.
  • You may also need to feed more slowly if you experience stomach upset or loose bowel movements immediately after your feedings.
  • Tap water is safe to use for most people. Ask your doctor if you need to use purified water.


Click here to watch the video:

Bolus feeding screen shot 1



  1. Jeanette Moore
    Posted August 14, 2016 at 9:43 am PST

    Just brought my husband home from nursing home with G tube. Did my first bolus feeding without medical supervision. My husband weighs 268lbs. and I was instructed to give him 2 cans of supplement every four hours for three feedings and the last feeding just give one can. I was advised to flush with 200 ml. of water before and after feedings. This seems like a large amount of water as compared to what I have read on the internet. Plus I do flushing before and after his medication which I give him twice a day. Would appreciate your opinion about this.

    Thank you.

  2. Posted August 15, 2016 at 3:22 pm PST

    Hi Jeanette, thank you for your question! Depending on the formula, your husband could be getting between roughly 1200-1400 milliliters of water from the formula itself. If you are adding 200 ml before and after each feeding (4 times) that adds up to a total of 2800-3000 ml in addition to what you use for medications. You can double-check with your health care professional that you are to add 200 before and after or just 100 before and after for a total of 200, but around 3000 ml of water daily seems about right for his weight as long as he is not on a fluid restriction per his doctor. This provides about 25 ml of water per kilogram of his body weight which falls in line with what is recommended. Of course it wouldn’t hurt to run it by his doctor just to make sure the instructions were interpreted accurately.

  3. Lorri Thomas
    Posted September 29, 2016 at 11:41 pm PST

    I am taking my Dad off the pump and going bolus. I am doing 250 ML/375 calories every 4 hours. Then on top of that the Dietitian told me to give 1500 ML of water. He is Bedridden. 92 years old. So id I do these at 11/3/7/11 then take him completely down off nutrition at night for 12 hours? Then can I give him the majority of the water over night? We give him med or water every 4 hours…Does that all sound right?

  4. Posted September 30, 2016 at 10:56 am PST

    Hi Lorri, it sounds like you are very organized and taking great care of your dad! As long as your are giving some water before and after his feedings to keep the tube unclogged…if the overnight water doesn’t cause any incontinence issues that should be fine. If you end up with accidents, you might want to see if you can split the water throughout the day. For example, you could give 185 ml before and after each feeding 4 times daily to pretty much meet the 1500ml. This may also be easier because you won’t have to worry about giving water at night. Hope that helps!

  5. sandy Smith
    Posted September 30, 2016 at 12:35 am PST

    Is it ok to do meds during the feeding? Or at the same time?

  6. Posted September 30, 2016 at 10:44 am PST

    Great question, Sandy! In order to prevent any interaction between medication and formula, it is advised to stop the feeding and flush your tube with water before administering medication. After the medication, you should flush the tube again. Then you can resume feeding. A clogged tube can be related to medication and formula coming in contact with each other.

  7. Dana P.
    Posted October 13, 2016 at 6:46 am PST

    Hi. My 13yr old son has a g-tube since birth. We are tubing bolus with 50% blender and 50% pediatric soy (Bright Beginnings). For breakfast, lunch and dinner we tube ~150mls over 10minutes, wait 10minutes and tube another 150mls. We also have another 210mls we tube at night. He seems to get pretty tired after the tubings. I’m just wondering if this is related to volume or rate of the feedings. I googled this and couldn’t find anyone discussing lethargy w/rate and volume. Any advice is greatly appreciated. Thank you!

  8. Posted October 13, 2016 at 7:58 am PST

    Hi Dana, thanks for your question! I wonder if the size of his meal his making him sleepy. You could try splitting his daily intake into 4 feedings and see if that helps.

  9. Carol
    Posted December 13, 2016 at 2:29 pm PST

    We feed our mother via bolus feeding through a g tube. We flush before and after, of course. When we pour the formula in, it goes in so slowly that we have to ‘chase’ it with a little water each time. Would it be ok to mix the formula in the beginning with some water in a measuring cup to thin it a little to hasten the flow into the tube? We would still flush before and after. Thanks for any info.

  10. Posted December 13, 2016 at 3:24 pm PST

    Hi Carol, thank you for your question! Some formulas are a little thicker than others, especially if they contain fiber or are concentrated in calories, such as those that are 1.5 to 2 calories per milliliter. As long as you are administering the formula with water immediately and it’s not sitting around, it should be okay to add some water to the syringe to thin the formula a little. You can also count the water you use toward your flushing water so you end up with the same amount of water each day.

  11. Arlyne
    Posted May 31, 2017 at 8:16 pm PST

    My husband gets 6 cans of Jevity 1.5 daily plus one bottle of Ensure with protein. We have him on 3 feedings of 2 cans a day but with our schedule we are wondering if we could go to 2 feedings of 3 cans each? Thank you for your help

  12. Posted June 2, 2017 at 8:35 am PST

    Thanks for your question, Arlene! It all depends on his tolerance. You could increase each feeding gradually to test it, for example start out with 2.5 cans at each feeding and see how he feels. If after a couple of days he doesn’t have any discomfort, nausea or loose stools, you could try 3 cans. That said, it’s probably better for him to stay on the 3 feedings because it spreads out his calorie intake to help regulate his metabolism. If you absolutely need to reduce the number of feeds to 2 per day, maybe you could still do the 3 feeds a day on some days, alternating between the 2 schedules. Hope that helps!

  13. Posted September 23, 2017 at 9:40 am PST

    My husband is age 77 , bedridden,has dementia from closed head trauma due to accident in Navy. I feed him via a PEG tube. For years we gave Jevity 1.5 three times a day via Bolus or pump. A nurse suggested we switch to Two Cal HN twice a day. I believe he has lost weight on the Two Cal. He is 6’2″ weighs 139 lbs. When we feed and the amount of water given is in direct correlation to the suctionings due to phlegm in his throat. Bolus is 60ml water before, 60ml feed, 60 ml after. We wait 1 to 2 hrs between feedings until the 237 ml can of Two Cal is gone. We give 2 cans a day. Is that enough feed and are we giving the feed and water too fast and too often?

  14. Posted September 25, 2017 at 10:17 am PST

    Hi Mary, thank you for your question! With the difference in treatment plans you mention, there is a deficit of 115 calories daily. Over time this could have led to weight loss. Was there a specific reason the change was made? He is also getting significantly less fiber. How are his bowel habits? Regarding the timing of his feedings, I’d recommend waiting 2-3 hours between each can of Two Can HN as it’s pretty concentrated. For more calories, you could add an additional half-can of the Two Cal HN in another feeding or you could try going back back to the the 3 cans of Jevity 1.5. Another option would be to syringe in a liquid protein supplement, such as Promod, which would contribute an additional 100 calories and 10 grams of protein.

  15. Heather Haynes
    Posted November 29, 2017 at 8:11 pm PST

    I watch a 18 month old with a Mickey button. I’ve never been trained, and can only go by what his mother has showed me. All his fluids are given through his tube, but he consumes most food orally. We give him 4ozs of pediasure at a time, every 3-4 hours. I was taking my time pushing them, but his mom just pushes it all straight in, in a matter of about 2 minutes. I started doing this as well. Is this safe? It doesn’t seem to bother him, but a client of mine, who is a nurse, seemed concerned. I just want to make sure, I’m not doing anything to harm him. Thank you in advance!

  16. Posted November 30, 2017 at 8:08 am PST

    Hi Heather, thanks for your question! It’s hard to answer without knowing anything about the child but if he tolerates it it’s probably okay. Watch for signs of intolerance, such as nausea, vomiting, abdominal distension or fussiness.

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