What patient position is used for a flex sigmoidoscopy?

• A. Supine
• B. Sims or Knee-Chest
• C. Prone
• D. Fowler's position

Answer: (B)

For a flexible sigmoidoscopy, the patient is placed in Sims or knee-chest position. This means lying on the left side with the knees drawn up toward the chest. This position aligns the rectosigmoid colon in a way that makes it easier to advance the flexible scope from the anal canal into the sigmoid colon, while also reducing looping of the instrument. Gravity helps shift gas and stool away from the instrument’s path, improving visualization and control and lowering the chance of irritation or injury. Other positions like supine (on the back), prone (on the abdomen), or Fowler’s (semi-upright) do not provide the same optimal alignment, making insertion more challenging and less comfortable for the patient.