Diverticulitis, Colonic

The objective of this clinical trial to evaluate the effectiveness and safety of outpatient treatment without antibiotics compared to outpatient treatment with antibiotics in patients with acute uncomplicated diverticulitis.
The hypotheses are:
* Null Hypothesis (H0): Outpatient treatment without antibiotics in patients with acute uncomplicated diverticulitis is neither safe nor effective and is inferior to outpatient management with antibiotics.
* Alternative Hypothesis (H1): Outpatient treatment without antibiotics in patients with acute uncomplicated diverticulitis is safe, effective, and not inferior to outpatient management with antibiotics.
We compare the rate of complications, therapeutic failure (clinical worsening and readmission) and recurrence between patients who, on an outpatient basis, are administered antibiotics and those who are not.
The patient diagnosed with acute uncomplicated diverticulitis who meets the inclusion criteria is evaluated and examined by a general surgeon. After informing him/her about the pathology, the study will be explained and he/she will be invited to freely participate in it. After accepting and signing the informed consent form, the patient will be included in the study and will be randomly assigned to one of the two treatment arms (outpatient treatment with antibiotics (group A) or without antibiotics (group B).

This observational study aims to test proteomics, metabolomics and proteoglycans as predictors of postoperative complications after colorectal surgery and as biomarkers of colorectal cancer.
The main questions to answer are:
* can these biomarkers predict anastomotic leakages
* can these biomarkers predict recurrence after colorectal cancer
* can these biomarkers be used as diagnostic tests for colorectal cancer
* can these biomarkers be identified in the tumor
Participants will undergo elective colorectal resection or stoma closure.

The goal of this clinical trial is to investigate the safety and effect of fecal microbiome transplantation (FMT) in patients with a former episode of acute colonic diverticulitis. The main question[s] it aims to answer are:
Is FMT in patients with a former episode of acute colonic diverticulitis a safe procedure without severe adverse events
What is the impact of FMT on patient-reported outcomes and re-admission rate
Participants will be asked to:
to ingest either 25-30 capsules with FMT or placebo capsules
Fill-in GI-QLI questionnaire prior to treatment/placebo and 3 months post baseline
Fill-in eating habit questionnaire
deliver blood-and stool samples prior to treatment/placebo and 3 months post baseline
In both the treatment and placebo group 5 patients will be offered sigmoideoscopy for mucosal biopsies if it is more than 2 items]. If there is a comparison group: Researchers will compare [insert groups] to see if [insert effects]