2 Answers

There's no concern that water will dilute the digestive juices or interfere with digestion. In fact, drinking water during or after a meal can actually improve digestion. Water and other liquids help break down the food in your stomach and keep your digestive system on track. Looking for other ways to promote good digestion? Focus on a healthy lifestyle. Eat plenty of fruits, vegetables and whole grains. Maintain a healthy weight. Include physical activity in your daily routine.

 Sourceshttp://www.mayoclinic.com/health/digestion/AN01776

Large quantities of nearly everything is uncomfortable.  
Generally, people are advised to drink 8 oz of water BEFORE a meal (not immediately before). The water tends to make one feel a bit fuller and the theory is  one will eat less.