Written and maintained by CASRAI Editorial Board
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This page describes products and general use; it is not medical advice.
A feeding tube clog (also called a blocked or occluded feeding tube) is a blockage inside the tube, or in the adaptor or extension set attached to it, that stops formula, water or medication from flowing. Clinic staff, carers and students usually search for it to learn why it happens, which product factors matter and when a clog is a matter for the clinical team. This page summarises a 2025 peer-reviewed review and a children’s hospital patient page, and it does not replace the instructions from the team that manages a particular tube.
What a feeding tube clog is
A clog means material has narrowed or closed the lumen, the channel inside the tube. A 2025 review in Frontiers in Medicine on nasoenteric tube dysfunction states that obstruction is known to occur in 25% to 35% of nasoenteric tubes, and that the type of tube, the type of enteral nutrition solution and giving drugs through the tube all contribute (Frontiers in Medicine, 2025). The same review reports that the risk of obstruction rises with the length of time the tube stays in place. Nasoenteric tubes in that review are 8 to 12 French (Fr) in diameter. Who uses these tubes: nurses and other clinicians, and carers or patients trained for home enteral feeding. For the tube types themselves, see what a feeding tube is and what a nasogastric tube is. For a tube that sits in the abdominal wall, see the G-tube button.
Why feeding tubes get blocked
The Frontiers in Medicine review and the SickKids patient page name the same short list of contributors. Each row cites where it comes from.
| Factor | What the source says | Source |
|---|---|---|
| Formula | Whole-protein formulas can coagulate with a large change in pH or when combined with strong electrolytes or alcohols; high-energy, high-protein, high-fibre formulas are more prone to blocking. | Frontiers in Medicine, 2025 |
| Medication | Adding drugs to the formula can destabilise it and raise the risk of obstruction. SickKids lists blockage by formula or medications as the usual causes. | Frontiers in Medicine, 2025; SickKids, 2025 |
| Time in place | Obstruction risk correlates positively with how long the tube has been indwelling. | Frontiers in Medicine, 2025 |
| Tube material and lumen | The review reports that medical-grade polyurethane tubes show better patency than silicone, and cites a study in which a 12 Fr tube blocked less often than 10 Fr or 8 Fr. | Frontiers in Medicine, 2025 |
| Adaptor, not the tube | The adaptor at the end of the tube can be the part that is blocked rather than the tube itself. | SickKids, 2025 |
Tube and set types that affect clogging
Two product choices show up in the evidence. First, material: the review describes medical-grade polyurethane as having a larger effective inner diameter than silicone at the same outer diameter, owing to its elasticity and flexibility. Second, lumen size: a larger lumen had fewer obstructions in the one study the review cites. See NG tube sizes for adults for the size range. Separately, the bag and extension set are part of the flow path, so a blockage can sit there rather than in the tube. See feeding tube bags. Enteral syringes and connectors follow the ENFit connector standard (ISO 80369-3); the equipment is described in irrigating a nasogastric tube.
Common mistakes
- Assuming the tube is blocked when the adaptor is the blocked part.
- Treating all tubes as equal: the review links material, lumen size and time in place to how often tubes block.
- Leaving a blocked tube unattended: SickKids notes that the longer a tube is blocked, the harder it may be to unblock.
When a clog means calling the care team
SickKids says to contact the tube specialist if the tube stays blocked, because the tube may need replacing. The review likewise says that in severe dysfunction the tube should be promptly removed and replaced by the clinical team. Unblocking methods, flushing routines and tube replacement are taught and decided by the team that manages the tube, so this page does not describe them.
FAQ
How to unclog a feeding tube?
Both sources treat this as a care-team matter, and both say a tube that stays blocked may need to be replaced by the clinical team. The method depends on the person and the tube, so follow the instructions from the team that manages it; this page does not give unblocking steps.
Why does a feeding tube get blocked?
Formula that coagulates, medication given through the tube, a long time in place, silicone material and a narrow lumen are the factors named in the review; SickKids also notes that the adaptor can be the blocked part. See the table above.
What are the steps of nasogastric tube feeding?
The steps depend on the formula, pump and local protocol and are taught by the care team, so this page does not list them. For the equipment, see irrigating a nasogastric tube and what a nasogastric tube is.
Sources
- Frontiers in Medicine (2025), “Multi-dimensional factors and intervention strategies for nasoenteric tube dysfunction: research progress and future perspectives”: https://pmc.ncbi.nlm.nih.gov/articles/PMC12698540/ (checked 2026-10-30).
- The Hospital for Sick Children (SickKids), AboutKidsHealth, “G/GJ tubes: What to do if your child’s feeding tube is blocked”, last updated 24 April 2025: https://www.aboutkidshealth.ca/ggj-tubes-what-to-do-if-your-childs-feeding-tube-is-blocked (checked 2026-10-30).
