A 47 year-old woman comes to the emergency department because of a two-day history of abdominal cramps and vomiting. She reports not passing stool or flatus during this time. She has no history of similar symptoms. She underwent an abdominal hysterectomy 12 years ago. Past medical history is otherwise unremarkable, and she does not take any medications. Her temperature is 37.7°C (99.8°F), pulse is 106/min, respirations are 18/min, and blood pressure is 134/68 mm Hg. On physical examination, auscultation of the abdomen reveals hyperactive, tinkling, high-pitched bowel sounds. Palpation of the abdomen shows distention and mild tenderness but no guarding or rebound. The rest of the physical examination is unremarkable except for mild tachycardia. Laboratory studies reveal the following:
C) Complete small bowel obstruction
Complete small bowel obstruction (SBO) occurs when there is either a partial or a complete blockage in the small bowel, commonly presenting with nausea, vomiting, and abdominal pain. In cases of partial SBO, some flatus may persist, while complete obstruction leads to obstipation. Various factors can cause SBO, with surgical adhesions and hernias ranking among the most frequent causes.
Answer choice A: Acute cholecystitis, is incorrect. Acute cholecystitis presents with fever, abdominal pain, and tenderness to palpation in the right upper quadrant, often in a patient with the history of gallstones.
Answer choice B: Colon cancer, is incorrect. Colon cancer most commonly occurs in the rectosigmoid region of the large bowel and can present with rectal bleeding or changes in bowel movements. Lesions within the ascending colon typically result in an exotic mass and slow bleeding, resulting in iron deficiency anemia. Colon cancer is unlikely to result in complete obstruction.
Answer choice D: Ileus secondary to renal failure, is incorrect. Ileus secondary to renal failure is less likely for this patient given her slightly abnormal creatinine which may be a prerenal manifestation from her vomiting. Ileus refers to intestinal hypomotility without a mechanical obstruction, most commonly occurring following surgery or in the setting of electrolyte abnormalities and typically presents with diffuse small and large bowel dilation.
Answer choice E: Perforated viscus, is incorrect. A perforated viscus typically presents with acute onset, diffuse abdominal pain with findings of abdominal rigidity, rebound tenderness, and guarding on physical examination (peritoneal signs). X-rays may reveal evidence of pneumoperitoneum, preferably obtained in an erect or left lateral decubitus position.
Key Learning Point
Complete bowel obstruction due to surgical adhesions occurs when bands of scar tissue form after abdominal surgery, leading to the bowels becoming stuck together or to the abdominal wall. This can create a blockage in the bowel, preventing the passage of food, fluids, and gas. As a result, symptoms such as severe abdominal pain, vomiting, and the inability to pass stool or gas (obstipation) can arise. Prompt medical attention is necessary to prevent complications.
