Thats because your health begins in your gut. :)
Yes, and flooding it with drugs is not the answer.
Side effects of Mesalamine:
Adverse Effects
Patients tolerate most 5-ASA formulations. However, adverse effects may include nausea, gastrointestinal upset, abdominal pain, headaches, nasopharyngitis, rash, arthralgias, agranulocytosis, aplastic anemia, myalgias, bone marrow suppression, oligospermia, hematuria, and cholestatic hepatitis. Renal impairment, including interstitial nephritis, nephrotic syndrome, and renal failure, can be seen and must be carefully monitored before initiating treatment and during treatment.[10][21]
Hypersensitivity reactions are also common, and there have been reports of pericarditis, myocarditis, hepatitis, nephritis, pneumonitis, and hematology-associated reactions. Patients may also be intolerant to 4-ASA, which causes symptoms such as cramping, headache, fever, malaise, pruritis, rash, and abdominal pain. Treatment must be discontinued if such issues occur.[22][23] Mesalaine-induced myocarditis has been reported, which may require discontinuation of 4-ASA.[24][25]
Drug-Drug Interactions
Antacids: Antacids may disrupt the pH-dependent formulations of 5-ASA. This condition can result in premature release and a decrease in the therapeutic effect of 5-ASA.[26]
Heparin: 5-ASA can enhance the pharmacologic effects of heparin and subsequently increase the risk of bleeding or bruising.[27]
Cardiac glycosides: 5-ASA may decrease the concentration of cardiac glycosides in the blood.[28]
Myelosuppressive agents (eg, mercaptopurine): Increase bone marrow suppression risk.[29]
H2 receptor blocker: H2 receptor blockers may increase gastrointestinal pH, cause premature release of 5-ASA, and decrease the therapeutic effect.
NSAIDs: Concomitant use of NSAIDs with 5-ASA increases the risk of nephrotoxicity.
Thiopurine analogs (eg, mercaptopurine): Interaction with 5-ASA may decrease the metabolism of thiopurine analogs.[29]
Proton pump inhibitors: Proton pump inhibitors may increase gastrointestinal pH, induce premature release of 5-ASA, and decrease the therapeutic effect.
Varicella vaccine: Increases risk of Reye syndrome and may enhance the toxic effects of these vaccines.[10]
https://www.ncbi.nlm.nih.gov/books/NBK551714/