bezoars are masses formed by the condensation of debris or stomach contents in the gastrointestinal tract . there are four major types of bezoars : a trichobezoar consists of hair , a phytobezoar of vegetable and fruit residues , a lactobezoar is formed from dairy products , a pharmacobezoar is caused by medications . a high - fiber diet , incomplete mastication , reduced gastric secretion , and decreased gastrointestinal motility from autonomic neuropathy can predispose patients to phytobezoar formation . it occurs more frequently in the small intestine , particularly in the terminal ileum and jejunum . the complications caused by bezoars are mechanical irritation , gastrointestinal obstruction , and , in severe cases , peritonitis caused by bowel perforation . bezoars are responsible for 0.44% of cases of mechanical intestinal obstruction , which occurs mainly in the stomach and small intestine . contrast - enhanced computed tomography ( ct ) is the method of choice to identify the location , severity , and etiology of intestinal obstruction . we describe our experience regarding a large - bowel obstruction caused by phytobezoar in a patient with a transplanted kidney . a 39-year - old man was admitted to our hospital for constipation , distension , and severe acute abdominal pain in the lower left quadrant . his medical history included alport syndrome resulting in progressive chronic kidney disease ( ckd ) , hypertension , and iron deficiency anemia under medical treatment . twelve years ago , he received a successful deceased - donor kidney transplant [ figure 1 ] . at the time of admission , vitals were stable , and he was afebrile . chest x - ray was normal and abdominal x - ray did not show signs of bowel obstruction . coronal computed tomography scan shows transplanted kidney in left iliac fossa (  ) non - contrast ct ( ncct ) of the abdomen was done ( toshiba  aquilion 64-tsx-101a / hc ) as the patient had ckd ( serum creatinine level = 7.71 mg / dl ) . ct scan revealed a focal circumferential thickening of the sigmoid colon with an ovoid and encapsulated intraluminal mass measuring 4.7  3.6 cm [ figure 2 ] . dilatation of the proximal segment with abundant fecal material was seen [ figure 2 ] . based on the ct findings , particularly mottled gas pattern and encapsulated wall of the mass , we made the diagnosis of phytobezoar . hence , because of acute intestinal obstruction and to avoid peritonitis , the patient underwent urgent exploratory laparotomy . ( a ) coronal computed tomography scan shows an ovoid intraluminal mass containing mottled gas pattern with encapsulating wall and associated wall thickening ( arrows ) ; note some dilated bowel loops ( stars ) and an abundant fecal material ( arrowhead ) . ( b ) the mean attenuation value of the intraluminal mass is about 10.21 hu the obstructive intraluminal mass in the sigmoid colon was identified ( approximately 4  4 cm in size ) and manually broken down with evacuation of the obstructive material along with large amounts of liquid fecal material . the postoperative course was uneventful and the patient was discharged on the seventh postoperative day . at 3-month follow - up , phytobezoars are concretions of poorly digested fruit and vegetable fibres that are found in the alimentary track and are mostly composed of indigestible cellulose , tannin , and lignin from ingested vegetables and fruits . normally , they are found in the stomach and may enter into the small bowel . the most important risk factors for phytobezoar formation are excessive consumption of fruits rich in fibers , poor dental health , insufficient mastication , diabetic gastroparesis , kidney failure , hypothyroidism , use of drugs which affect gastric motility , and previous gastrointestinal surgery . in our case , other symptoms include abdominal distension , vomiting , constipation , diarrhoea , anorexia , and weight loss . if treatment is delayed , colonic bezoars can be complicated by intestinal obstruction and perforation with consequent peritonitis . plain abdominal radiography and ct scan are used for radiological evaluation of the patients presenting with intestinal obstruction . simple abdominal x - ray may reveal air - fluid levels associated with mechanical obstruction , and occasionally it is possible to see the outline of bezoar , which is difficult to differentiate from abscess or feces within the colon . on abdominal ct , 89% of bezoars appear as spherically - shaped masses containing air - fluid levels . ct is also helpful in discriminating bezoars from other causes of bowel obstruction such as gastrointestinal malignancies , gallstone ileus , etc . in our case indeed , many authors have highlighted some ct features to allow easier differential diagnosis between these two entities . small bowel feces tends to be more amorphous and tubular in shape without evidence of an encapsulating wall , whereas phytobezoars have a well - defined ovoid shape and an encapsulating wall , such as in our case . chen et al . showed that a higher grade of obstruction is commonly associated with phytobezoar impaction without mesenteric fatty stranding and intraperitoneal fluid ; moreover , they found that a combination of the food debris length < 9.5 cm and the mean attenuation value < 11.75 hu of the obstructed bowel at the transition point was suggestive for phytobezoar , such as in our patient . although these features are typically found in the small bowel , they may also be considered very useful in the large bowel . conservative management is considered in uncomplicated cases of colonic bezoars and consist of digital evacuation , enemas and manual disimpaction . if conservative approach fails , a colonoscopy can be attempted for bezoar removal with contextual mechanical fragmentation and extraction using several instruments . although endoscopy has an acceptable success rate and fewer complications than surgery , surgical approach is mandatory in case of endoscopic treatment failure , sigmoid volvulus , hematochezia , intestinal obstructions , perforations , or peritonitis . when surgical approach is chosen , the first step is intestinal decompression and fluid - electrolyte replacement ; later , open or laparoscopic abdominal exploration may be performed . in our case , the patient underwent laparotomic surgery and phytobezoar was manually broken down with evacuation . bezoar is a rare disorder , however , it must be suspected in case of mechanical intestinal obstruction . our case underlined the importance of early detection and removal of a bezoar to prevent complications such as obstruction , perforation , or peritonitis .
bezoars are masses formed by the concretion of stomach contents or debris within the gastrointestinal tract . 
 bezoars are rare and account for only 0.44% of all cases of gastrointestinal obstruction and mainly occur in the stomach or small intestine . intestinal obstruction caused by colonic bezoars 
 is extremely rare . 
 a 39-year - old man with a transplanted kidney came to the hospital because of abdominal pain , constipation , and distension . 
 we performed an abdominal computed tomography scan and found an ovoid intraluminal mass with a mottled gas pattern in the distal sigmoid colon . 
 subsequently , the patient underwent laparotomic surgery and removal of the bezoar . 
 we report a rare case of large bowel obstruction due to colonic phytobezoar , which was confirmed intraoperatively .