Introduction

An ingested fish bone could either be harmless or harmful. It may pass uneventfully through the GIT moved down by the peristalsis. Being a sharp object, it can also be potentially dangerous capable of perforating into the digestive tract and surrounding organs including the heart, liver, spleen, and lungs. A Medline search (with the keywords fishbone+ perforation) revealed multiple case reports describing perforation of various internal organs. Though it is mentioned in medical literatures that fish bone is one of the known foreign bodies causing rectal perforations, it is surprising that no official report describing such case was found on the quick search.

Case Report

A 67 years old diabetic (Insulin Dependent Diabetes Mellitus) gentleman presented to the Emergency Department with chief complaints of generalized abdominal pain and distension associated with constipation but no vomiting. The pain was dull and non-radiating. There was no passage of stools or flatus since five days.

He recalled ingestion of fish bone a month ago. He claimed that he accidentally swallowed a fish bone during the meal time which was initially stuck on his throat. It was dislodged and went down easily causing prickly sensation along the guts for a month. Abdominal discomfort was noted on the previous week. Three days ago, an excruciating sharp object obstructed along the rectum was felt which he extracted manually. It was the fish bone (Figure 1) which incurred severe pain and mild bleeding.

Figure 1

Figure 1: Shows the discolored and partially broken fish bone (about 1.25 inches long) that caused the rectal perforation.

He attended a nearby Primary Health Clinic where he received Xylocaine jelly and Dulcolax tablet which offered no relief .The abdominal pain and distention had aggravated over 4 days instead. This patient has a history of hypertension and insulin dependent diabetes mellitus.

On examination, the patient was fully conscious, afebrile and toxic-looking. Blood pressure was 140/70mmHg with the pulse rate at 100 beats per minute. There was no dyspepsia, no vomiting and no any signs of bleeding. The abdomen was tense and tender with tympanic tone. Rectal exams revealed empty rectum with severe tenderness. Upon auscultation, there was a sluggish bowel movement and reduced bowel sounds. Significant laboratory findings revealed: WBC – 10.10, Haemoglobin Count – 15.9 g/L, and random Blood glucose – 18.9 mmol/L. Fentanyl 100 mg injection was given for pain. Intestinal Obstruction was suspected but the abdominal supine X-ray did not manifest any evidence of intestinal obstruction (Figure 2). General Surgeon was notified and abdominal and pelvis CT scan with contrast was done (Figure 3). It showed minimal air pockets around the rectum which most likely represent rectal perforation. There was no sign of bowel of ischemia however the visualized part of the lung showed deepened bilateral atelectatic changes.

Figure 2

Figure 2. The abdominal X-ray showing no evidence of acute intestinal obstruction.

The patient was admitted as the case of Rectal Perforation and Acute Peritonitis. Series of investigations and diagnostic procedures were done and he underwent exploratory laparotomy. There was no significant improvement after the first surgery. Despite of the extensive antibiotics regimen, he developed multiple rectal abscesses and necrotizing fascitis which later caused septic shock. Second exploration was performed. The patient survived all the surgical procedures but systemic infections and severe respiratory infections and complications became inevitable which required a tracheostomy. He stayed 4 months in surgical intensive care unit and was onwards moved to the surgical ward.

Figure 3

Figure 3: The abdominal and pelvis CT scan with contrast showing air pockets on the rectum.

Discussion

Accidental fish bone ingestion is a common occurrence not regarded as highly threatening event. Because fish is a regular part of human meal, bone ingestion turned out to be an inevitable associated risk on the daily eating activities. A retrospective study of 1,338 patients conducted in a Chinese hospital by Lai et.al revealed that fish bone (62.7 per cent) was the commonest type of foreign body ingested. ₂ Most ingested foreign bodies pass through the GIT uneventfully within 1 week ₃ however owing to the bone sharpness; it may potentially cause perforation of vital internal organs. It may be successful in its harmless passage but may possibly lodge at the anorectal junction. Usually, foreign bodies become lodged in the mid rectum, where they cannot negotiate the anterior angulations of the rectum. They can be felt on digital examination. With adequate sedation, most RFBs can be extracted transanally either in the emergency department or operative suite under direct vision.₄ If the foreign object is palpable and can be visualized; a local anaesthetic is given by subcutaneous and submucosal injections of 0.5% lidocaine. The anus can be dilated with a rectal retractor and the foreign body grasped and removed. Removal of a rectal foreign body may be of high risk and should be done by a surgeon or gastroenterologist skilled in foreign body removal. Batho and Szanto stressed the importance of the removing of the foreign bodies as soon as possible in any acute abdomen.₅ Abdominal examination and chest X-rays may be necessary to exclude possible intraperitoneal rectal perforation. Sigmoidoscopy is required following extraction to evaluate mucosal injury or perforation.₄ Operative intervention is needed in minority of the patients who developed signs of perforations, peritonitis, bleeding, obstruction, and pelvic sepsis.₆ Possible intervention could include a proctoscopy, sigmoidoscopy retrieval of RFBs, or laparotomy with subsequent stoma, closure of perforation or Hartman's procedure.

The reported patient was fully aware of the presence of the fish bone on his GIT but due to absence of any serious symptoms, it was just ignored. His bowel discomforts which he believed to be due to a common constipation and his sensation of the presence of rectal foreign body prompted to self extraction of the obstructing fish bone causing some pain and mild bleeding. In cases like this, every medical practitioner must have high suspicion of the potential injuries and complications lying underneath that may have been incurred by a sharp foreign object. A detailed clinical history and physical examination are essential for the diagnosis and management of any lesions.₇ The patient may be asymptomatic or may manifest presentations of a florid peritonitis. Acute peritonitis is frequently caused by perforation and presented as a sudden, severe abdominal pain. High fever develops rapidly with nausea, vomiting and paralytic ileus.₈ As the bacterial infection spreads to affect the peritoneum in general, the condition becomes serious and septic shock may develop. Proper investigations and appropriate management is mandatory. With the presence of diabetes mellitus, any rectal injury should not be taken lightly. Perforation by a fish bone is not an ordinary tale to tell.

Conclusion

Though the severity of the patient's condition could be partly attributed to the existing precipitating factors (diabetes mellitus, atelectatic changes of the lungs, and old age), rectal foreign bodies which includes fish bones should generally be considered potentially harmful. Due to the potential complications imposed, rectal injuries incurred should be regarded seriously and treated expeditiously.

Acknowledgement

Correspondence to

Gamal Mohamed El Sherbiny, MRCSEd (A&E) Main A&E Department #65 King Khalid University Hospital P.O. Box 7805, Riyadh 11472 Kingdom of Saudi Arabia Tel.: +966502862721 E-mail: sherbiny64@hotmail.com