Unresolved tube occlusions have resulted in concretion of enteral feeds, tearing of the tube, and direct administration of feeds to the esophagus, as well as possible formation of esophageal bezoars.
Dandeles, L. and Lodolee, A. Efficacy of Agents to Prevent and Treat Enteral Feeding Tube Clogs. The Annals of Pharmacotherapy. 2011. 45:676-680
Capnography is the monitoring of the concentration or partial pressure of carbon dioxide (CO2) in respiratory gases. This can help clinicians determine when an NG/NE tube has taken an inadvertent course into the trachea during the insertion process.
Powers, J, Brown, B, Lyman, B, et al. Development of a competency model for placement and verification of nasogastric and nasoenteric feeding tubes for adult hospitalized patients. Nutr. Clin. Pract. 2021; 36: 517-533. https://doi.org/10.1002/ncp.10671
In one study over a 5-year period, 95 incidents were reported to the National Reporting and Learning System in which substances were inadvertently administered through NG tubes into the respiratory tract, resulting in 32 patient deaths.
Powers, J, Brown, B, Lyman, B, et al. Development of a competency model for placement and verification of nasogastric and nasoenteric feeding tubes for adult hospitalized patients. Nutr. Clin. Pract. 2021; 36: 517-533.https://doi.org/10.1002/ncp.10671
Some Liquid medications contribute to tube clogging when exposed to enteral nutrition formula. Liquid syrups, for instance, cause clumping and lead to tube clogging. 
lansoprazole oral suspension granules, sucralfate suspension, and mineral oil are known to clog feeding tubes.
Schallom, Marilyn. “How to Recognize, Prevent, and Troubleshoot Mechanical Complications of Enteral Feeding Tubes.” American Nurse, 23 July 2020, www.myamericannurse.com/recognize-prevent-troubleshoot-mechanical-complications-enteral-feeding-tubes/.