A rare cause of partial intestinal obstruction in a child: colonic lithobezoar

Abstract

The accumulation of undigested foreign bodies or nutrients in the gastrointestinal tract forming a conglomeration is called a bezoar. Bezoars are referred to according to the foreign bodies that constitute their core: phytobezoar (fibres or seeds of vegetables and fruits), trichobezoar (hair), lactobezoar (remnants of milk) and lithobezoar (rock or similar substances).

BACKGROUND

Although they can be found in any part of the gastrointestinal system, the stomach is the most common site for bezoars. Primary colonic bezoar is an exceptionally rare situation. Up until 2007, only four colonic lithobezoars are thought to have been reported in the literature. This report aims to present the clinical and surgical features of a 4-year-old male patient, with a previous history of pica and iron deficiency anaemia, who underwent pebble extraction from the colon after being diagnosed with partial intestinal obstruction.

CASE PRESENTATION

A 4-year-old male patient was admitted with abdominal pain, distention and vomiting. His medical history revealed an absence of defaecation for the past 2 days; this had followed a decrease in the frequency and volume of defaecation for the past week. In addition, he had a history of pica.

Physical examination demonstrated abdominal distention, hyperactive bowel sounds and multiple, irregular masses in both lower quadrants. Rectal examination revealed a rock solid, thorn-like mass filling the entire rectal lumen. Extraction of some of these masses turned out to be pebbles.

A complete blood count revealed the following: white blood cells 24.1×10⁹/l, haemoglobin 60 g/l, haemotocrit 0.211, mean corpuscular volume 52.2 fl, platelets 372×10⁹/l. He had evident hypochromic microcytic anaemia. His C-reactive protein was 32 mg/l. Renal and hepatic function tests were within normal limits.

Abdominal x ray revealed dense opacities in the pelvis and in the descending colon. In addition, there were some small air–fluid levels at the left upper quadrant.

After appropriate premedication, anal dilation was performed under general anaesthesia. Various pebbles of different sizes were extracted with the help of colonic lavage and bimanual manoeuvres. After confirmation of the luminal integrity with rectosygmoidoscopy, the procedure was ended.

He was followed-up with intermittent enema during the postoperative period, and this helped with the extraction of the residual pebbles.

DISCUSSION

An accumulation of undigested foreign bodies or nutrients in the gastrointestinal tract forming a conglomeration is called a bezoar. Bezoars are referred to according to the foreign bodies that constitute their core: phytobezoar (fibres or seeds of vegetables and fruits), trichobezoar (hair), lactobezoar (remnants of milk) and lithobezoar (rock or similar substances).

Although they can be found in any part of the gastrointestinal system, the stomach is the most common site.¹ Phytobezoars are more common in childhood, whereas lithobezoars are very rare. It is thought that only 13 cases of colonic bezoar have been reported in the literature.²

Primary colonic bezoars are extremely rare. It is thought that only four colonic lithobezoars had been reported in the literature up until 2007.³ Although they usually present with classic abdominal symptoms such as distention, pain and vomiting, in some cases they can lead to mortal complications. Clinical findings differ according to the settlement site. Whereas oesophageal bezoars lead to dysphagia, reflux and retrosternal pain, gastric bezoars present with abdominal pain, nausea, vomiting, loss of appetite, weight loss, ulcerations and perforations. Intestinal bezoars lead to partial or complete obstruction or intestinal perforation. Colonic bezoars cause abdominal pain, constipation and, in particular, obstruction at the rectosigmoid level. Recurrent episodes of abdominal pain, vomiting and abdominal distention were also seen in our patient.

Bezoars can be insidious or present with severe complications; however, a careful medical history and physical examination can facilitate the diagnosis. Bezoars are rare among children. Most of the childhood cases consist of children with mental retardation or a history of pica. Our case had a positive pica history. Abdominal palpation can reveal these thorn-like masses. This finding is referred to as the “colonic crunch sign”.⁴ Abdominal x ray is particularly important in the diagnosis of colonic lithobezoars. The presence of numerous radiopaque masses in the lower abdomen or the rectosigmoid junction, referred to as “corn on the cob”,⁴ is pathognomonic for lithobezoars. Our patient also demonstrated this finding with colonic gas distention and some small air–fluid levels at the left upper quadrant (fig 1).

Figure 1.

A plain abdominal x ray showing innumerable dense opacities (“corn on the cob” sign) especially congregated in the rectosigmoid area and small air–fluid levels at the left upper quadrant with colonic gas distention.

Sedation, anal anaesthesia and colonic lavage are among the first-line management options. Laparotomy can be considered for resistant cases. Our patient benefited from anal dilation performed under general anaesthesia, followed by colonic lavage and bimanual manoeuvres, which rendered laparotomy unnecessary.

Colonic lithobezoars can lead to partial or complete intestinal obstruction. Lithobezoars should be kept in mind in patients presenting with obstruction findings, particularly in those with a previous history of pica.

LEARNING POINTS

• An accumulation of undigested foreign bodies or nutrients in the gastrointestinal tract forming a conglomeration is called a bezoar.

• Although bezoars can be found in any part of the gastrointestinal system, the stomach is the most common site

• In the case reported here, a rare colonic lithobezoar is described.