The authors would like to report this case of a 12-year-old girl with an impacted watermelon seed rectal bezoar who presented with abdominal pain and diarrhoea.
N presented to hospital with lower abdominal pain. She emigrated with her family from Iraq 6 months prior to this presentation. The pain was associated with nausea and loose bowel motions.
She was seen by the surgical team and diagnosed with acute appendicitis. A laparoscopic appendicectomy was performed, but the appendix was macroscopically normal (histopathology later demonstrated no inflammatory changes).
Her pain persisted postoperatively and she developed diarrhoea with episodes of faecal incontinence. There was no blood or mucus in the diarrhoea.
Her inpatient care was transferred to the paediatric team. On clinical examination her abdomen was diffusely tender; bowel sounds were audible. Perianal examination was normal. On repeated history her mother revealed that N had eaten a large quantity of dried watermelon seeds 24 h prior to the onset of the abdominal pain.
A per rectal (PR) examination was performed. A hard, ‘grainy’, impacted mass was felt. It was manually disimpacted. N passed a number of pellets of hard fibrous material in the next few hours and her pain was completely relieved. She continued to have diarrhoea containing seed-like particles for the next 36 h then her stools became solid. Stool microscopy and cultures were returned negative.
Her mother brought in the half-consumed packet of dried, salted watermelon seeds the following day.
Rectal seed bezoar is a common cause of faecal impaction in children in the Middle East. In a retrospective review of faecal impaction from Israel, 89% of cases were caused by rectal seed bezoars, the most common of which is watermelon seeds (other seeds implicated were prickly pear seeds, sunflower and pumpkin seeds).1 All the children with seed bezoars were of Arab descent.1 A similar review by the same group in adults demonstrated that 55% of faecal impaction was caused by seed bezoars with a similar ethnic association.2 The authors assert the ethnic association is through dietary preferences. Multiple other case reports highlight the severity of the pain associated with this condition and the common requirement for disimpaction under general anaesthesia.3,4 There have also been cases reported of overflow (paradoxical) diarrhoea associated with rectal seed bezoars.5 In adults, rectal perforation has resulted.6
This is an unusual condition to encounter in Australia. It highlights the need, in a multicultural society, to remember the possibility of unusual diagnoses. It also reminds us of the dying art of PR examinations –‘If you don't stick your finger in, you stick your foot in!’