AIM: to compare the clinical and diagnostic features and quality of life in patients with different types of idiopathic megabowel.

   PATIENTS AND METHODS: 157 patients with idiopathic megacolon/megarectum, confirmed by barium enema, were divided on 3 groups: 1) distal idiopathic megabowel (megarectum ± distal third of sigmoid colon dilatation); 2) idiopathic megacolon (variable extent of colon dilatation with a normal size rectum); 3) idiopathic megabowel (megarectum ± variable extent of colon dilatation). Hirschsprung’s disease was excluded in all patients based on complex of clinical features, barium enema and anorectal manometry results and (if needed) rectal Swenson’s biopsy.

   RESULTS: the cohort included 70 (44.6 %) patients with distal idiopathic megabowel, 50 (31.8 %) patients with idiopathic megacolon and 37 (23.6 %) patients with idiopathic megabowel. Wexner constipation scale rate, rate of integral parameters “abdominal discomfort” and “defecation difficulties”, summary assessment of quality of life by IBSQOL questionnaire did not differ between groups (p > 0.05). At the same time patients with distal idiopathic megabowel were statistically significant younger (p < 0.01), had significant higher rate of faecal incontinence due to faecal impaction overflow (p < 0.01), had less often bowel movement. Also these patients had significant higher rate of distal contrast retention (p < 0.01) during gut transit test, but their colonic transit time was slight faster (p = 0.04).In multivariate analysis both megarectum (OR = 25.42; 95 % CI 5.01–128.92) and insufficiency of anal sphincter (OR = 4.71; 95 % CI 1.38–16.14) were independent predictors of faecal incontinence. The surgical treatment was performed most often in idiopathic megacolon group (p < 0.01), mainly due to colon volvulus. The most patients with distal idiopathic megabowel (97.1 %) were successfully maintained with a conservative treatment.

   CONCLUSION: there was not substantial difference in clinical features and quality of life in patients with different types of idiopathic megabowel, except of significant higher rate of faecal incontinence and less often bowel movement in distal idiopathic megabowel group. Faecal incontinence in these patients is linked disturbance rather intestinal, than anal component of continence. The necessity in surgical treatment was rising most often in cases of idiopathic megacolon. The conservative treatment was quite effective in most patients with distal idiopathic megabowel.

   AIM: to improve the results of chronic anal fissure treatment.

   PATIENTS AND METHODS: the study included 22 patients randomized by random numbers generation method into 2 groups. Eleven patients were included in main group and were treated with 0.3 % nifedipine + 2.0 % lidocaine gel, 11 patients of the control group received injections of botulinum toxin A into the internal anal sphincter at a dose of 80 U (BTA 80).

   RESULTS: by day 30, there was a decrease of maximal resting pressure in anal canal (MRPAC) in both the main and control groups [p = 0.015 and p = 0.004, respectively] and the average resting pressure in anal canal (ARPAC) [p = 0.01 and p = 0.02, respectively]. There was no difference between the groups in pain severity both after stool and during the day (p = 0.5 and p = 0.6, respectively). On day 60, the defect was epithelized in 6/11 (54.6 %) patients of the study group and in 9/11 (81.8 %) patients of the BTA 80 group [p = 0.36], respectively. The reason of treatment failure in 4/11 (36.4 %) patients of the main group and 2/11 (18.2 %) patients of the control group was a preserved internal sphincter spasm. It was found that these patients used a lower amount of the drug product — 2.2 (1.8; 2.5) mg/day compared to 2.4 (1.9; 2.7) mg/day in other patients. On the day 30 after surgical treatment, complaints about gas incontinence were registered in 1/11 (9.1 %) patients of the main group and 1/11 (9.1 %) patients of the control group [p = 1]. Such a complication as external hemorrhoid thrombosis occurred only in 1/11 (9.1 %) patients in the BTA 80 group [p = 0.87].

   CONCLUSION: the study results show that gel containing 0.3 % nifedipine and 2 % lidocaine produces an effect on the tone of the internal sphincter comparable to BTA. However, the lack of accurate dosage of the drug product and/or low patient compliance reduce the effectiveness of treatment and make the use of BTA preferable for medical relaxation of the internal sphincter.

   AIM: to improve the algorithm and results of surgical treatment of combat wounds of the rectum.

   PATIENTS AND METHODS: thirty-one patients with combat injuries of the rectum were included in the cohort.

   RESULTS: twenty-seven (87.1 %) patients were discharged in satisfactory condition, 4 (12,9 %) patients died. Sepsis developed in all four patients: in two of them sepsis was on the background of necrotising fasciitis and one had peritonitis. Endoscopic control revealed 10 wounds of the extraperitoneal part of the rectum undiagnosed at the 1^st and 2^nd stages of medical care. Surgical care included all four main components: diverting stoma, distal washout (mechanical cleansing of the rectum to clear water), suturing of the lesion through perineal access, drainage or tamponisation of the presacral space was done in 20 (64.5 %) patients. Endoluminal VAC therapy was used in 12 patients. In 11 of them, VAC treatment was successful with complete healing of rectal wall wounds.

   CONCLUSION: the four-component treatment approach is the optimal option for wounds of the extraperitoneal part of the rectum. Diverting stoma and distal bowel washout prevents severe infection. Endoluminal VAC therapy, in some cases, can be used as an alternative to presacral drainage and suturing of the rectal wall lesion.

   AIM: to present the primary experience of performing intracorporeal linear colorectal anastomosis using the “overlap” technique in laparoscopic anterior rectal resection.

   MATERIALS AND METHODS: the study presents the outcomes of intracorporeal linear “overlap” anastomosis in patients who underwent laparoscopic anterior rectal resection between October 2023 and February 2024. The results were evaluated based on various parameters including operation time, the postoperative morbidity rate (by Clavien-Dindo scale), conversion rates, hospital stay, quality of life by SF-36 questionnaire 30 days after surgery.

   RESULTS: the linear “overlap” anastomosis was done in 10 patients (5 females), aged 62.0 ± 9.03 years and BMI of 27.5 ± 7.2 kg/m². No intraoperative complications occurred. One patient developed a seroma at the incision site (Clavien–Dindo I). The first bowel movement was at 1 (0–3) days after surgery. The post-op hospital stay was 5.7 ± 1.9 days.

   CONCLUSION: primary results demonstrate the simplicity and safety of intracorporeal linear “overlap” anastomosis technique. The further advanced study is justified.

   AIM: to assess early and late results of the evagination method for the treatment of rectovaginal fistulas (RVF) in patients with anal incontinence due to muscle defect in the anterior semicircle.

   PATIENTS AND METHODS: the study included 45 patients. The prevailing etiology of RVF was delivery lesion in 19/45
(42.2 %). The median follow-up was 6 (4; 8.5) months. On day 30 after surgery, the outcome was assessed clinically. Late outcomes were assessed in all patients 3–12 months including clinical control, transanal ultrasound and sphincterometry.

   RESULTS: recurrence occurred in 9/45 (20 %) patients. The significant improvement of continence was revealed: in mean pressure in rest (p = 0.004), in maximum contraction pressure (p < 0.0001), in Wexner incontinence score (p < 0.0001). With a fistula opening less than 16 mm, the recurrence risk increases (p = 0.0003).

   CONCLUSIONS: the evagination method is effective option in extent septal defects and correcting additional anal
sphincter insufficiency.

   INTRODUCTION: the wound following Transanal Endoscopic Microsurgery (TEM) is traditionally closed by suturing. However, some studies suggest that leaving the wound open after TEM might be a viable alternative.

   STUDY OBJECTIVE: to compare two methods of managing rectal wounds in patients after TEM.

   PATIENTS AND METHODS: patients were divided into 2 groups: the main group (open wound management) and the control group (suture wound management). The primary endpoint of the study was the morbidity rate. The secondary endpoints included the need and duration of antibacterial therapy, post-op hospital stay, the severity of the inflammatory response, the wound healing time and the quality of life.

   RESULTS: from November 2021 to November 2023, 177 patients were included in the randomized study: 68 in the open wound management group and 109 in the suture wound group. The analysis included 50 patients in each
group. It was found that the operation time in the main group was significantly shorter (30 (20; 40) minutes versus 55 (40; 60), p < 0.0001). The infectious complications rate was lower in the open wound management group: 11/50 (22 %) versus 16/50 (32 %), p = 0.26; the postoperative bleeding rate was higher: 4/50 (8 %) versus 2/50 (4 %), p = 0.7. Post-op hospital stay did not differ: 6 (4;7) days versus 6 (5; 7), p = 0.22. The duration of antibiotic therapy for infectious complications was longer in the open wound management group: 6 (5;6) days versus 5 (5;6.5), p = 0.02. In the case of infectious complication the inflammatory response was higher in the group of the open wound management: white blood cell counts (15.9 (14.3; 19.5) × 109/L versus 13.1 (12; 15.6) × 109/L, p = 0.01) and temperature (38.6 ± 0.7 °C versus 38 ± 0.6 °C, p = 0.02). Wounds in both groups healed by the 30^th day, and the quality of life did not differ between groups.

   CONCLUSION: the results of the randomized study demonstrated the efficacy and safety of open rectal wound management after TEM.

   AIM: to identify the genotype-phenotype correlation in children with familial adenomatous polyposis (FAP) and to assess the risk of surgery.

   PATIENTS AND METODS: a retrospective study included children with FAP from January 2000 to December 2023. For analysis they were divided in two groups (“severe” and “non-severe” genotype) according to the results of the genetics.

   RESULTS: forty-two patients from 36 families with FAP were included in the study. Statistical analysis revealed that the mean age at the time of surgery was significantly different and was 13 ± 4 years in the “severe” genotype group vs. 16 ± 1 in the “non-severe” group (p = 0.04). The age of first colonoscopy (OR: 0.74, 95 % CI: 0.53–0.94, р = 0.03) and the carpeting of polyps (OR: 8.06, 95 % CI: 1.71–81.1, р = 0.04) were significantly associated with severe genotype.

   CONCLUSION: the “severe” genotype is characterized by earlier onset of the disease and age of colonoscopy, of polyps carpeting.

   AIM: to assess the length of the stump of the feeding arteries of the right colon, their anatomical location relative to the superior mesenteric vein (SMV), the level of ligation of the main arteries after right hemicolectomy with D2- and D3-lymphadenectomy.

   PATIENTS AND METHODS: the retrospective study included 82 patients with a histologically confirmed right colon cancer aged 44-88 (mean 68) years. All patients underwent right hemicolectomy. In 40 cases, D2 lymph node dissection was performed, in 42 cases — in D3. Preoperatively, all patients were assessed for the location of the ileocolic and right colon arteries relative to the SMV and the expected length of their stumps was measured by CT. Postoperatively, the actual length of the stumps was assessed.

   RESULTS: CT images of the ileocolic artery stump were obtained in 76 (92.6%) of 82 patients. In 6 patients, a metal clips were installed along the contour of the superior mesenteric artery; in such cases, a clear CT image of the stump of the ileocolic artery was not obtained, and the length of the stump was assessed as 0 mm. The stump of the right colic artery was determined in all patients in whom the artery was identified preoperatively. The ventral location of the ileocolic artery relative to the SMV according to CT data was identified in 38 (46.3 %) of 82 patients, the dorsal location — in 44 (53.7 %) of 82 patients. With the ventral location of the ileocolic artery relative to the SMV in patients with D2, the length of the artery was 14.3 (8-25.6) mm, with D3 — 7.6 (3.3–11.1) mm (p = 0.005). With the dorsal location of the ileocolic artery relative to the SMV in patients with D2, the length of the artery was 8.8 (4.9–16.2) mm, with D3 — 3.9 (1–6.9) mm (p = 0.004).

   CONCLUSION: the actual length of the stump of the feeding artery can become an indicator of the level of ligation of the main arteries and, indirectly, the extent of lymphadenectomy after right hemicolectomy. Further studies with a larger number of cases are needed to confirm the hypothesis for measuring the length of the stump of the feeding arteries as a marker of the extent of the procedure performed.

   AIM: to compare the efficacy (fistulas healing rate) and safety (morbidity rate) of mesenchymal stem cells (MSC) and placebo in patients with perianal fistulizing Crohn’s disease (PFCD).

   PATIENTS AND METHODS: a systematic review and meta-analysis of clinical trials, comparing the results of treatment of PFCD with single local administration of MSCs or placebo was performed. The meta-analysis included 5 randomized clinical trials and the results of treatment of 289 patients were analyzed.

   RESULTS: the meta-analysis demonstrates the high efficacy of a single local administration of MSCs for PFCD compared with placebo (OR = 2.10, CI 1.28–3.46, p = 0.003). The most common postoperative complications — abscesses and fistulas — are probably associated with the natural course of the disease and do not differ significantly between the groups. The results of surgery may be affected by the type, source and concentration of MSCs, the method of delivery and the number of injections.

   CONCLUSION: local administration of mesenchymal stem cells is an effective and safe method for perianal fistulas in Crohn’s disease, however, the presence of significant limitations in the meta-analysis makes it cautious about the results obtained and requires further randomized trials.

   Colorectal cancer (CRC) is the third in prevalence among oncological diseases worldwide and second in the structure of oncological mortality. Genetic assessment of CRC is a necessary stage during selecting further treatment for patients. Many studies demonstrate a diverse distribution of mutations in the KRAS, NRAS, and BRAF genes in CRC. A critical literature review was conducted in order to systematize data on the mutational profile and genetic heterogeneity of these driver mutations in Russian patients with CRC. Articles were searched for in open databases. Totally 17 Russian studies and 3 English meta-analyses were analyzed for comparison with Russian data. Mutations in the KRAS, NRAS, and BRAF genes, according to Russian and international studies, are found in 40 %, 4 %, and 7 % in CRC patients, respectively. The frequency and specific localization of mutations may depend on the geographical location and nationality of the cohort. High intertumoral and intratumoral heterogeneity in CRC, especially in KRAS gene mutations, significantly influences the choice of further therapy and underscores the need for more detailed study of the mutational profile of the primary tumor, affected lymph nodes, and distant metastases. In Russia, several molecular genetic methods are used to determine somatic mutations in CRC with different sensitivity and specificity, the most common is real-time PCR. More accurate diagnostic methods include digital droplet PCR, Sanger sequencing, and next-generation sequencing, but each method has its limitations that must be considered when planning diagnostics and research. The promising directions in personalized oncology is the study of gene copy number variations, which may contribute to the development of new methods for treating CRC in the future. Despite the large number of studies, some aspects of the mutational profile of CRC in Russian studies remain poorly understood, which is why further research is needed on patients with colorectal cancer in Russia.

   AIM: to analyse and synthesize Russian and foreign literature, to get acquainted with the concept of oxaluria, its types, transport mechanisms of oxalate transport in the intestine and the relationship between hyperoxaluria and inflammatory bowel diseases in order to identify possible options for therapeutic action on the mechanisms of development of these pathologies.

   MATERIALS AND METHODS: the literature review was based on the Internet data, including bibliographic directories, books, journals, and original articles. The literature sources used for the article reflect the essence of the described problem to the fullest extent possible and can be useful for both practicing physicians and students of medical universities.

   RESULTS: the gastrointestinal tract through epithelial transport of oxalate plays an exclusive role in oxalate homeostasis and hyperoxaluria. Metabolism of dietary oxalate and the formation of endogenous oxalate, its secretion, absorption, transport and biodegradation by intestinal microflora may influence the excretion of this compound by the kidneys. Knowledge of the interrelated relationships of the gut-kidney axis, mechanisms of transport, transport and biodegradation of oxalate, especially in inflammatory bowel disease, is of great importance for understanding the pathophysiology of hyperoxaluria as a risk factor for urinary stone formation with a point of pharmacological action in the gut. This literature review introduces the concept and forms of oxaluria, shows the classification of oxaluria, describes each form, and broadly explains the metabolism and mechanisms of oxalate transport in the human body. Special attention is given to intestinal hyperoxaluria and anion exchangers belonging to the large multifunctional SLC26 gene family, most of which are expressed throughout the gastrointestinal tract. The authors emphasise their current role in intestinal oxalate transport, as well as methods of possible drug action on the mechanisms of hyperoxaluria.

   CONCLUSION: a multidisciplinary approach is needed to address the problems of intestinal hyperoxaluria and, consequently, the treatment of urolithiasis. The role of newly identified intestinal and renal anion exchangers is not fully understood, hence the targets and mechanisms of action on these types of exchangers with the possibility of preventing the development of urolithiasis are not fully understood. Further randomised studies on the problem under investigation are needed.

   Currently scientists from different countries are exploring the possibilities of using machine learning methods to improve the accuracy of endoscopic and radiation diagnostics in patients with inflammatory bowel diseases (IBD) both to reduce the time spent by doctors on describing the results and to reduce the time needed to verify the diagnosis. Predicting the course of IBD based on artificial intelligence (AI) with the creation of predictive scenarios (models) is another promising area in gastroenterology. This review analyzes the main directions of scientific projects on the introduction of AI and machine learning methods in the diagnosis and prediction of the course of IBD. The article pays special attention to the problems faced by specialists in the application of AI methods, ways to solve them, as well as the prospects for using AI in patients with IBD. The possibilities of using AI for colorectal cancer screening and analysis of medical records are presented.