In medicine, a foreign body is any object lying partially or wholly within the body that originated in the external environment. Foreign body placement is voluntary or involuntary. Common voluntary acts will include cosmetic reasons, e.g. earrings (or other body piercings) and iatrogenic e.g. surgical clips; occasionally however the object has been inserted into natural and unnatural cavities for sexual or nefarious purposes. Conversely involuntary placement is usually as a result of an accident e.g. motor vehicle collisions, stepping on broken glass, gunshot wounds, or explosions 1-7.
Most rectal foreign bodies are inserted via the anus, although occasionally the foreign body has been ingested and has passed through to lie in the rectum. Commonly, rectal foreign bodies are used for sexual purposes 1-3. Rectal foreign bodies have a large variety from sex toys to light bulbs to vegetables. The main problem with this is the often delayed presentation due to the reluctance of patients to present to emergency departments. Patients may suffer from extraperitoneal mucosal injuries or suffer from a more severe complication such as perforation 1-5.
Two plain radiographs are recommended to accurately demonstrate the size, shape and location of the rectal foreign body. This should be performed before a digital examination to prevent staff-related injuries from sharper foreign bodies.
Ingested foreign bodies range from children putting whatever they want in their mouths, mental-health related issues of swallowing strange objects (pica), to bones stuck in the pharynx or gastrointestinal tract. Coins account for 70% of paediatric ingested foreign bodies; coins will typically become ‘stuck’ at the level of the cricopharyngeus muscle 8,14. As a rule of thumb, coins visualised in the sagittal plane (acquired while entering through vocal cords) on anteroposterior radiographs are in the trachea, whereas coins in the oesophagus will have a coronal orientation on frontal chest radiographs.
An important alternative to consider when assessing coin-like objects are button batteries. These are very similar in appearance to coins, but typically have a slight step in profile with an inner ring when viewed en face. Button batteries can be potentially fatal when in contact with surrounding tissue as they can generate an electric current that will lead to the formation of sodium hydroxide resulting in severe, potentially fatal mucosal damage 6,13,14.
Sharp ingested foreign bodies can be potentially problematic when lodged in the oesophagus, patients will often require emergency endoscopy, more often than not if the sharp object is within reach of endoscopy it will be removed before it progresses further 12.
Plastic bread clips are diagnostically challenging, the limited literature on this foreign body suggests they are invisible on both plain radiography and CT, and the rigid shape can cause bowel perforations or gastrointestinal haemorrhage 15,16.
Most soft tissue foreign bodies are involuntary, resulting from an accident. The most commonly reported soft tissue foreign bodies are glass, metal and splinters from wood 5. It is imperative to locate foreign bodies before they become infected or worse damage close by organs.
Metal, glass and stone can be visualised very well using conventional plain film radiography, whereas more organic structures, such as wood, may require further imaging such as ultrasonography 5-7.
Commonly, aspirated foreign bodies will have a clear clinical correspondence: choking, coughing, neck pain or struggling to breathe. The right main bronchus is the most common site of obstruction due to the anatomy of the bronchial tree favouring the right side (larger diameter, more vertical orientation). Often two orthogonal plain radiographs are the primary investigation of choice 12.
Drug packing is a well-documented foreign body; it is also one of the most common recorded anal foreign bodies. Often drugs are concealed within condoms, foil, latex or cellophane, then swallowed or inserted anally or vaginally. These should be considered hazardous to the patient until evacuated due to the possibility of the concealment method rupturing.
The investigation of foreign bodies relies heavily on radiology and every foreign body will have an optimal modality for investigation 17.
The radiological appearance in plain radiography of foreign bodies is dependent on three factors: the x-ray attenuation of the foreign body, the surrounding structures and any overlying structures that may veil the object.
The anatomical location will not only affect the radio-opacity of the suspected foreign body, but the rate of magnification as the object is placed further or closer to the detector, lateral cervical radiographs can have a magnification rate of up to 21.6% 9-11.
Most foreign bodies are hyperechoic.
The density of the foreign material in the body can range markedly, so use of multiple window settings is crucial in identifying the presence of the objects. Ruotuinely, soft issue, lung and bone windows should be assessed. Certain plastics may be occult on CT.
The signal intesity of the foreign material in the body can range markedly, but most objects cause artefact of some sort. Certain obects may be occult on MRI, such as those made of wood and plastic.
- 1. Coskun A, Erkan N, Yakan S et-al. Management of rectal foreign bodies. World J Emerg Surg. 2013;8 (1): 11. doi:10.1186/1749-7922-8-11 - Free text at pubmed - Pubmed citation
- 2. Nivatvongs S, Metcalf DR, Sawyer MD. A simple technique to remove a large object from the rectum. J. Am. Coll. Surg. 2006;203 (1): 132-3. doi:10.1016/j.jamcollsurg.2006.03.012 - Pubmed citation
- 3. Akhtar MA, Arora PK. Case of unusual foreign body in the rectum. Saudi J Gastroenterol. 2009;15 (2): 131-2. doi:10.4103/1319-3767.48973 - Free text at pubmed - Pubmed citation
- 4. Cohen JS, Sackier JM. Management of colorectal foreign bodies. J R Coll Surg Edinb. 1996;41 (5): 312-5. Pubmed citation
- 5. Aras MH, Miloglu O, Barutcugil C et-al. Comparison of the sensitivity for detecting foreign bodies among conventional plain radiography, computed tomography and ultrasonography. Dentomaxillofac Radiol. 2010;39 (2): 72-8. doi:10.1259/dmfr/68589458 - Free text at pubmed - Pubmed citation
- 6. Hunter TB, Taljanovic MS. Foreign bodies. Radiographics. 2003;23 (3): 731-57. doi:10.1148/rg.233025137 - Pubmed citation
- 7. Eggers G, Welzel T, Mukhamadiev D et-al. X-ray-based volumetric imaging of foreign bodies: a comparison of computed tomography and digital volume tomography. J. Oral Maxillofac. Surg. 2007;65 (9): 1880-5. doi:10.1016/j.joms.2006.09.029 - Pubmed citation
- 8. Jayachandra S, Eslick GD. A systematic review of paediatric foreign body ingestion: presentation, complications, and management. Int. J. Pediatr. Otorhinolaryngol. 2013;77 (3): 311-7. doi:10.1016/j.ijporl.2012.11.025 - Pubmed citation
- 9. Halverson M, Servaes S. Foreign bodies: radiopaque compared to what?. Pediatr Radiol. 2013;43 (9): 1103-7. doi:10.1007/s00247-013-2660-y - Pubmed citation
- 10. Shigematsu H, Koizumi M, Yoneda M et-al. Magnification error in digital radiographs of the cervical spine against magnetic resonance imaging measurements. Asian Spine J. 2013;7 (4): 267-72. doi:10.4184/asj.2013.7.4.267 - Free text at pubmed - Pubmed ci
- 11. King RJ, Craig PR, Boreham BG et-al. The magnification of digital radiographs in the trauma patient: implications for templating. Injury. 2009;40 (2): 173-6. doi:10.1016/j.injury.2008.06.027 - Pubmed citation
- 12. Weiland ST, Schurr MJ. Conservative management of ingested foreign bodies. J. Gastrointest. Surg. 2002;6 (3): 496-500. Pubmed citation
- 13. Litovitz T, Whitaker N, Clark L et-al. Emerging battery-ingestion hazard: clinical implications. Pediatrics. 2010;125 (6): 1168-77. doi:10.1542/peds.2009-3037 - Pubmed citation
- 14. Sahn B, Mamula P, Ford CA. Review of foreign body ingestion and esophageal food impaction management in adolescents. J Adolesc Health. 2014;55 (2): 260-6. doi:10.1016/j.jadohealth.2014.01.022 - Pubmed citation
- 15. Tang AP, Kong AB, Walsh D et-al. Small bowel perforation due to a plastic bread bag clip: the case for clip redesign. ANZ J Surg. 2005;75 (5): 360-2. doi:10.1111/j.1445-2197.2005.03356.x - Pubmed citation
- 16. Newell KJ, Taylor B, Walton JC et-al. Plastic bread-bag clips in the gastrointestinal tract: report of 5 cases and review of the literature. CMAJ. 2000;162 (4): 527-9. Free text at pubmed - Pubmed citation
- 17. Martin L. Gunn. Pearls and Pitfalls in Emergency Radiology. ISBN: 9781139619899