E-numbers are an EU invention. Over 900! assigned. Obviously the work of a committee of some sort.

The E-number list makes it clear that many products assigned an E-number are safe.

Additives with an E-number and classed as safe include riboflaven (vitamin B2), agar, guar, chlorophyll, curcumin (tumeric), most carotenes, calcium carbonate, gold, anti-oxidants including vitamins C and E, etc., etc. Many are natural in vegetables, many are often recommended by physicians.

Many are listed as causing stomach upset, including citric acid (in all citrus fruits); others are "suspicious." Some cause allergies in certain people. The list requires common sense and, in many cases, specialized knowledge to interpret.
Health food faddists will find some of their favorites listed.

Some are controlled in their use, but this is not stated.

List here: http://www.curezone.com/foods/enumbers.asp

Guest sounds like a chronic dyspeptic.