Respected user, hi I evaluated your query thoroughly. *First of all remove stigma from your mind that you have low immunity power at the age of 18. *Treatment before 2 years has nothing to do with present condition. *Follow simple easy steps in your routine & see the difference with time : - keep BE POSITIVE principle in the life , whatever happens its your inner strength matters to take you out from every worst condition in this world. - have plenty of liquids to maintain your hydration. - have diet rich in proteins, iron, multivitamins, minerals , anti-oxidants, carbohydates. - take more green leafy vegetables, cereals , pulses, legumes , yoggurt, fibers , fruits for better digestion. - do regular walking , exercises, YOGA at home without failure. - avoid stress / anxiety . - keep your weight, BP , Blood sugar & cholesterol levels under control. - have sound sleep of 8 hours. - keep fix timings of breakfast , lunch , dinner - avoid prolong fasting / overeating - avoid going to sleep for 2 hours atleast after lunch / dinner. - avoid smoking / alcohol / abuse substances if any using . - engage yourself more in your liked activities . - help your friends who have same problem. - if abdominal pain is cumbersome can go for Ultrasonography of Abdomen & Pelvis . Hope this clears your query. Thanks for using Health Care Magic & keeping trust in our medical services. Wishing you a very happy healthy life ahead. Welcome for any health related issues in future. Regards dear take care.