In this case showing an unusual association of diseases and conditions, we have hypothesised that the patient, being depressed with a latent form of mental illness associated with behavioural disorders, caused by poor concentration, loss of interest and so forth (typical of depression according to International Classification of Disease 10 criteria), may have ingested crude, moist, unwashed vegetables or plants, which amazingly harboured a Crustacean Isopod.
The patient presented with signs and symptoms of intestinal obstruction. The usual sequence of investigations for the diagnostic assessment of bowel obstruction starts with plain AXR. If the plain AXR shows air fluid levels and grossly distended bowel loops, the level and possible site of obstruction must be assessed (ie, small bowel or large bowel) and the further diagnostic work-up proceeds accordingly. When in doubt, or when the clinical and radiological findings are not clear enough to suggest the best further diagnostic steps, abdominal CT scan may be helpful with the eventual adjunct of triple contrast (intravenous, oral and/or rectal).6
The CT scan showed in our patient a mechanical SBO with a transition zone and intraluminal mass suspected to be a bezoar.
A bezoar is a mass of undigested food, hair or other material, which becomes lodged and impacted in the gastrointestinal tract. They are classified according to their content as phytobezoars, trichobezoars, lactobezoars, mixed medications bezoars or bolus food bezoars.7
Phytobezoars are constituted by concretion of poorly digested fibres from vegetables and fruits. They are an uncommon cause of mechanical gastrointestinal obstruction. They are often found in the stomach and are usually a consequence of gastric surgery (such as gastric resection or partial gastrectomy or truncal vagotomy). Previous gastric surgery interferes with the stomach motility and, therefore, predisposing to bezoars formation; other factors include high fibre dietary intake, poor mastication, diminished gastric secretion and motility, hypothyroidism, autonomic diabetic neuropathy and myotonic dystrophy. The phytobezoars rarely may pass through the pylorus into the small bowel. Primary small bowel bezoars are particularly rare8
and are mainly seen related to underlying diseases such as diverticula, strictures or tumours. Stagnation within a dilated bowel segment, such as in Crohn's disease, may also facilitate their occurrence. However, phytobezoars occurring in an intact gastrointestinal tract are exceptionally rare.9 10
It raises the suspicion for other possible pathophysiologic mechanisms together with predisposing factors such as dietary and eating habits.
The gastrointestinal tract is a commonly primary involvement site for parasites during their life cycle. The common intestinal parasitic diseases include amebiasis, ascariasis, anisakiasis, strongyloidiasis, ancylostomiasis, trichuriasis and tapeworm disease.
Isopods are the most diverse in form and the most species-rich crustaceans belonging to the same subclass as lobsters and crayfish. They are distantly related to trilobites; extinct Arthropods appeared in the early Cambrian period and throughout the lower Paleozoic era. Both trilobites and isopods are in the class Arthropoda (‘jointed legs’), but trilobites are distinguished by the three lengthwise sections of the body. Modern isopods are common inhabitants of nearly all environments. The isopoda range in length from 0.5–500 mm. Phylogenetic analysis and the fossil record suggest that the group dates to at least the Carboniferous period of the Paleozoic approximately 300 million years ago. Isopods live most abundantly on the sea bottom from the abyss to the intertidal zone. The group has also successfully colonised freshwater and marine habitats.
Some isopods are parasitic living on other crustaceans or in the mouths or on the gills of fish. Terrestrial isopods are successful colonisers of land but are poorly adapted to it and usually confined to microhabitats where temperatures are moderate and damp surfaces are available as already described by Spencer and Edney in 195411
and Hadley in 1994.12
They emerge primarily at night or whenever the temperature drops and the relative humidity of the air increases to forage for food.13
- SBO is mainly secondary to postoperative adhesions (60–75% of the cases); however, the unusual cases, such as the intraluminal obstructing causes (eg, gallstones, bezoars, parasitic/helminthic infection, foreign bodies), should not be neglected since they account for perhaps 1 in 20 cases of such a common condition.
- Phytobezoars should be considered in the differential diagnosis of intestinal obstruction in patients over the age of 50 years, especially if they are presenting mental disorders, medical history of gastric surgery, have poor dentition and eat fibre-rich food.
- In the diagnostic work-up, plain abdominal film allows the diagnosis of intestinal obstruction and the involvement of the small bowel; however, CT scan of the abdomen is useful for both confirming the diagnosis of obstruction, the location and the cause (especially if intraluminal identifying the concretion of vegetable fibres) and for the decision to perform emergency surgery as well. Ultrasound might also be useful in the identification of intraluminal bezoars or foreign bodies.
- The treatment may be medical non-operative in selected patients with partial obstruction. However, particularly in the presence of a bezoar, early surgical treatment is recommended to prevent strangulation.
- Whenever possible, the bezoar should be manually fragmented and milked through the caecum. Laparoscopic fragmentation maybe useful in such cases. If this is not feasible, the bezoar should be extracted via enterotomy or, if it is difficult due to the large size of the bezoar or in presence of bowel ischaemia, bowel resection and anastomosis is warranted. Finally, a thorough examination of the entire intestinal and gastric segments should be performed to exclude the presence of any other bezoars.