Approximately 20% of caustic ingestions result in some degree of esophageal injury. Alkaline materials are the most frequent corrosive materials ingested.     The physical form and PH of ingested materials play a critical role in the site and type of gastrointestinal injury (PH > 12 or PH < 1.5, crystalline drain cleaners). Unlike Alkaline solutions, strong acids are bitter, burn on contact and...