Regarding the formal diet, you need to be on the exclusion diet for 8 weeks before attempting to reintroduce foods. This takes about one year to do properly. You will still experience unexplained flare ups. I would not suggest attempting the fodmap diet in the UK without speaking to a nutritionist first. You will need a go referral.
The AMT is the excess of the tentative minimum tax over the regular tax. Thus, the AMT is owed only if the tentative minimum tax is greater than the regular tax. The tentative minimum tax is figured separately from the regular tax. In general, compute the tentative minimum tax by:
Preferences and Adjustments Positive and negative AMT adjustments are added or subtracted from regular taxable income to determine the taxable income after AMT adjustments. Tax preference items are then added to get your AMTI. The following is a list of AMT adjustments: Adjustments for AMT (deductions not allowed): Standard deduction and personal exemptions; Certain itemized deductions; Mortgage interest; Taxes; Medical expenses; Miscellaneous deductions; Investment interest; MACRS depreciation; Basis adjustment affects AMT gain or loss