Differential Diagnosis for Post-Colonoscopy Distended Abdomen and Respiratory Distress

Single Most Likely Diagnosis

• Perforation of the colon: This is a well-known complication of colonoscopy, especially if the procedure involved polyp removal or if the colon was over-distended. The perforation can lead to free air in the abdominal cavity, causing abdominal distension and potentially compromising respiratory function due to increased intra-abdominal pressure.

Other Likely Diagnoses

• Post-procedure ileus: Although less immediately dangerous than a perforation, an ileus (a condition where there is a temporary halt of the normal contractions of the bowel muscles) can cause significant abdominal distension and discomfort. Respiratory distress could be secondary to the distension.
• Bowel obstruction: If the colonoscopy inadvertently caused a twist or kink in the bowel, or if a polyp removal site caused a stricture, this could lead to an obstruction. Obstructions can cause abdominal distension and, if severe, can lead to respiratory compromise.

Do Not Miss Diagnoses

• Pneumoperitoneum not due to perforation (e.g., from insufflation): While less common, it's crucial to consider that some air introduced during the colonoscopy might not be absorbed immediately, potentially causing abdominal distension. However, this would typically not cause significant respiratory distress unless the amount of air was substantial.
• Cardiac complications: The stress of the procedure, especially in patients with pre-existing heart conditions, could potentially lead to cardiac issues such as myocardial infarction or arrhythmias, which might present with respiratory distress.
• Pulmonary embolism: Although rare, the immobilization and potential dehydration associated with the procedure could increase the risk of venous thromboembolism, including pulmonary embolism, which would cause respiratory distress.

Rare Diagnoses

• Splenic injury: Rarely, the manipulation during colonoscopy could potentially cause injury to the spleen, especially if the spleen is enlarged or if there are adhesions. This could lead to abdominal distension due to hemorrhage and potentially cause respiratory distress if the hemorrhage is significant.
• Hemorrhage: Significant bleeding from a polyp removal site or from the colonoscopy itself could lead to abdominal distension and, if severe, to hypovolemic shock and respiratory distress.