## 3 Results
### The Role of the Enteric Nervous System in IBS
Despite the development of sustained-release medications like capsules and tablets, their efficacy is restricted, and they have demonstrated advantages only in a subset of individuals with IBD [119; 120; 121]. As an example, Sandborn et al. discovered that while anti-TNF-\(\alpha\) monoclonal antibody therapy was effective for many patients, it necessitated a higher dosage [122]. Moreover, as time progressed, up to 50% of patients experienced diminished effectiveness, accompanied by heightened risks of adverse reactions like lymphoma, infections (especially the recurrence of tuberculosis), and lupus-like syndrome [123]. Moreover, conventional medicines can often result in side effects such as allergic reactions, nausea, and pancreatitis [124]. Figure 4: 5-HT as a key modulator of gut–immune crosstalk and inflammation in IBS. We created this image with Canva. Thus, assuring that medications used for colorectal inflammation treatment are effective and safe is of utmost importance. To tackle this problem, sophisticated targeted nanomaterial drug delivery systems (NDDSs) have been created. These systems facilitate the delivery of drugs to inflamed regions, reduce their absorption by healthy tissues, and enhance their effectiveness. NDDSs employ nanotechnology to produce nanomaterials comparable in scale to biomolecules and viruses, making them perfect for cellular recognition and uptake. Since the 1930s, vaccines have incorporated nano-sized aluminium adjuvants, and lipid NPs have recently been investigated for messenger RNA (mRNA) delivery. By 2022, more than 90 nanomedicines had received global approval, with around 60 approved by the U.S. FDA and about 30 by the Pharmaceuticals and Medical Devices Agency. NDDSs have demonstrated the ability to improve IBD treatment by enhancing drug bioavailability, shielding drugs from gastrointestinal acidity, and targeting them at sites of inflammation. This increases their therapeutic effectiveness while reducing drug exposure to healthy tissues [125; 126; 127; 128]. Moreover, targeted NDDSs can focus drugs at the sites of inflammation, which lowers the necessary dosage and improves effectiveness by utilising inflammatory tissue-specific ligands to aim at particular cells [129]. The results show that NDDSs aimed at specific targets can enhance IBD therapy by directing drugs to inflamed tissues, limiting contact with healthy tissues, and decreasing adverse effects [130; 131; 132]. In summary, inorganic, organic, and polymeric nanocarriers can serve as NDDSs for drug delivery in IBD treatment, with their biological effects affected by factors such as shape, size, and physicochemical properties [133]. Inorganic nanocarriers are promising due to their simple preparation, stability, and ability to load drugs effectively; however, they encounter clinical safety issues [134]. On the other hand, organic nanomaterials from animal and plant sources can also function as efficient drug carriers, offering advantages such as high biocompatibility, low toxicity, controlled release, and regulation of gut microbiota. However, despite their clinical potential, they face challenges such as unstable preservation and decomposition due to gastric acid.