Comparison of gastric emptying of solid and semi-solid meals using real-time ultrasonography in healthy Sri Lankan adults.

Background: Routine assessment of solid gastric emptying is challenging due to the prolonged test duration and complex meal preparation. Replacing solid test meals with easily prepared, commercially available semisolid meals and shortening the test duration can significantly enhance the feasibility and practicality of gastric emptying evaluations.

Aim: To compare the gastric emptying and antral motility of solid vs semi-solid meals of similar volume and nutritional consistency, and to assess the feasibility of meal substitution and reduction in test duration during the solid gastric emptying assessment.

Methods: Thirty healthy volunteers (17 males, age: 29.4 ± 6.0 years, body mass index: 23.4 ± 2.94 and 13 females, age: 37.2 ± 11.9 years, body mass index: 22.9 ± 4.34) underwent gastric emptying by real-time ultrasonography after a solid meal and a comparable commercially prepared semi-solid meal (each meal, total calorie 350 kcal, carbohydrates 60%, fat 30% and proteins 10%), on separate dates 1 week apart. The gastric antral area was measured at 5 minutes, 15 minutes, 30 minutes, 45 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 210 minutes, and 240 minutes post-ingestion using a previously validated technique and compared between meals.

Results: Mean and median antral areas, gastric emptying rates, gastric residual ratios, and motility index at each time point were almost similar between meals for up to 3 hours. At the end of 4 hours, the mean emptied percentage of the semisolid meal and solid meal was 81.1% and 70.6%, respectively. The emptying rate of the semisolid meal at 90 minutes significantly correlated with that of 240 minutes. There was no correlation between the solid meal emptying rates at 90 minutes and 240 minutes.

Conclusion: Gastric emptying, residual antral cross-sectional area and antral motility of a semisolid meal are almost similar to that of a solid meal of the same nutritional value until three hours post-ingestion. A semisolid test meal can effectively substitute a solid test meal during ultrasound assessment of gastric emptying, without compromising the validity of the results. Additionally, the ease of preparation and administration of semisolid meals enhances the overall feasibility of gastric emptying assessments.