Participants are given a minimum of 1500 mL of a preparation of mannitol as oral contrast agent over an hour prior to the examination.

Participants are given a minimum of 1500 mL of a preparation of polyethylene glycol as oral contrast agent over an hour prior to the examination.

Experimental group was given polyethylene glycol as oral contrast agent.

The assessment system includes six parts.

1. Whether the contrast reached the caecum is evaluate and recorded as 'yes' or 'no'.
2. The overall presence of inhomogeneous contrast is evaluated and recorded as 'yes' or 'no'.
3. The maximum dimension of a single loop in each quadrant was recorded.
4. The scale of loops of small bowel distended ≥2 cm are evaluated and recorded as '0-25%', '26-50%', '51-75%' and '76-100%'.
5. The wall visibility and visualization of the small-bowel mucosal are scored on a scale ranging from 1 to 4, in which a higher score represents a better outcome.
6. Overall quality is assessed subjectively by the radiologist and scored on a scale ranging from 1 to 4, in which a higher score represents a better outcome.

The degree of nausea, emesis, diarrhea, abdominal distension and cramp following ingestion are scored on a scale ranging from 0 to 10, in which a higher score represents a higher level of these targets.