Honey, I Shrank the Beads: Water Bead Growth and Shrinking in Different Solutions In Vitro

Water beads expand by absorption and are used as toys and decorations among other purposes. When ingested, they have been implicated in small bowel obstructions. Laxatives have been administered after ingestion to prevent obstruction. Our primary aim was to evaluate the growth patterns and maximal diameter of various water beads in multiple solutions. Our secondary aim was to identify a liquid capable of shrinking expanded water beads.

Water beads (10 standard-size brands; 3 jumbo) were tested for growth and shrinking. Growth was assessed in 9 clinically relevant liquids (eg, tap water, simulated gastric fluid) and shrinkage in 4 (Gastrographin, Omnipaque, honey, and Gatorade). Diameter was measured at intervals for 96 hours. Expanded beads were transferred to shrinking solutions and measured for 24 hours.

Standard-size water beads grew to a maximum range of 0.9 cm to 1.7 cm. Jumbo beads grew to a maximum range of 4.9 to 6.0 cm. All brands grew in polyethylene glycol. Gastrographin and honey shrank expanded jumbo beads (mean diameter decrease at 24 h of 31% and 32%, respectively).

In vitro growth of water beads demonstrates that standard-size beads do not grow larger than most blueberries and are unlikely obstructive culprits, but jumbo beads can grow larger than a golf ball. Water beads substantially expand in polyethylene glycol, which puts into question its use as a laxative to treat water bead ingestions. Gastrographin and honey shrink water beads; clinical utility should be explored.