Hello You mentioned that after every 20 -30 days , you get fever and this responded to anti malarial treatment . But you suffer with stomach discomfort . So when you take these tablets for malaria take these with pantoprazole-d and also take some antacid ( if it contains oxetacaine ,will be better). But main question is ,why fever after 20-30 days and respond to anti malarial tablet. This time when you get fever , just wait for 3 days and only take tylenol ( paracetamol 650 mg whenever high fever , as high fever with chills and rigor are the characteristic feature of malaria). After 3 days because of life cycle of these parasites . After 3 days fever get in blood for malarial parasite as well card test for malarial parasite . Whatever the result ,take chloroquine 600 mg base stat ,followed by 300 mg after 6 hour . Later on day 2&3 , single doses of 300 mg/day. After this take PRIMAQUINE 15 mg daily for 14 days and this is WHO recommended radical treatment . Not forget to use pantoprazole-d and antacid . This is all about malaria . Now ,why fever , so beside malaria such type of fever may be due to , these possibilities ,these include. 1 Typhoid fever , get in blood for Widal test and serology test for diagnostic purposes. 2 Urinary tract infection , diagnosis can be confirmed by urine culture . 3 Septicaemia chronic , get in blood culture for any chronic infection and also drug sensitivity test and whole thing will be clear. Since this is prescription , so consult a physician and get his help. Good luck. Anemia and drug fever are another reason of such fever.