FMT Breaks the Deadlock of Refractory Diarrhea in a Patient with Multiple Comorbidities:
MDT Decision for a Post-Gastrectomy Gastric Cancer Patient with Cirrhosis

This article is a de-identified educational case review. It describes the clinical course of one patient managed at Beijing Arion Cancer Hospital and reflects the team's approach to multidisciplinary decision-making when multiple comorbidities complicate a single symptom. It is not medical advice, nor does it guarantee outcomes for other patients. Treatment decisions must be individualized by qualified physicians.

Case Introduction

This issue discusses a 61-year-old man who had undergone gastric cancer surgery and carried multiple underlying diseases — 20 years of chronic hepatitis B, more than 10 years of cirrhosis, splenomegaly and decreased counts across all three blood cell lines — while suffering persistent diarrhea for 3 years and 9 months. After antispasmodics, probiotics, antibiotics, traditional Chinese medicine and many other lines of treatment, his symptoms waxed and waned. Working out the cause meant simultaneously distinguishing tumor recurrence, cirrhosis-related intestinal dysfunction and post-surgical malabsorption, creating a double bind of "complex comorbidities versus difficult causal differentiation" and "ineffective conventional therapy versus high treatment-safety requirements". The diagnostic and treatment process offers an MDT template for "building a cause-screening system for refractory diarrhea with multiple comorbidities and the individualized delivery of fecal microbiota transplantation (FMT)", while also pointing toward the direction of further exploration after a "partial response" in a complex case.

I. Case Overview: Baseline Status and Core Challenges

1. Baseline Status

The patient was a 61-year-old man admitted for "diarrhea for 3 years and 9 months". In August 2021 he underwent subtotal gastrectomy (the specific procedure, pathology type and stage are unknown; no postoperative radiotherapy or chemotherapy was given, and follow-up was irregular). Less than 4 months after surgery, diarrhea appeared without obvious trigger, accompanied by abdominal colic before defecation that eased afterward, 5-10 bowel movements per day, moderate volume, and no bloody or tarry stool.

Treatment history: He had consulted local hospitals and several hospitals of traditional Chinese medicine, receiving antispasmodics (pinaverium bromide), probiotics (bifidobacteria), antibiotics (rifaximin tablets), various Chinese medicines and patent medicines, digestive enzymes, enteric-coated pancreatin tablets and whole-nutrient supplements, with symptoms fluctuating. Probiotics had been stopped 2 months earlier and rifaximin 20 days earlier; for the past 10 days he had been taking oral Chinese medicine plus digestive enzymes, enteric-coated pancreatin tablets and whole-nutrient formula (1 bottle/day). In the last 3 days there had been no obvious diarrhea or abdominal pain, and he was admitted for further diagnosis and treatment.

Comorbidity history: Chronic hepatitis B for 20 years; splenomegaly and cirrhosis for more than 10 years; coronary heart disease and hypertension for more than 4 years (blood pressure returned to normal after gastric cancer surgery, and antihypertensive drugs were no longer taken); a history of pulmonary nodules; and reduced white blood cells (WBC), red blood cells (RBC) and platelets (PLT) discovered less than 4 months after gastric surgery and persisting for 4 years. Personal history: 40 years of alcohol use, averaging 3 liang to 1 jin of liquor per day; no smoking. Family history: his father died of liver cancer, and there is a family history of hepatitis B.

2. Core Challenges

Diagnostic dilemma: The patient's diarrhea had lasted a long time against a complex background, and the cause could involve many factors — post-gastrectomy malabsorption (resection of the gastric antrum and most of the gastric body), cirrhosis-related destruction of the intestinal mucosal barrier and dysbiosis, and nutritional and metabolic abnormalities related to hypersplenism. Imaging showed that a July 2025 gastroscopy found post-subtotal-gastrectomy changes and esophageal varices, while colonoscopy found perianal varices; an October whole-digestive-tract contrast study showed segmental luminal dilation at the junction of the roughly 2nd and 3rd groups of the small intestine; and PET-CT found no clear evidence of tumor recurrence or metastasis, indicating only comorbidity-related changes such as cirrhosis, splenomegaly and gallstones. In laboratory tests, repeated stool routine examinations and bacterial and fungal cultures found no pathogens, and norovirus and rotavirus were negative; but a November 2025 gut microbiota test clearly showed increases in harmful bacteria across the gut-brain axis (Fusobacterium, Sutterella and others), the gut-skin axis (Peptostreptococcus, Sutterella and others) and the gut-metabolism axis (Holdemanella, Acidaminococcus and others), with a Prevotella-type enterotype, alongside a raised carcinoembryonic antigen (CEA) of 5.78 ng/mL — so the relative weight of tumor-related factors and dysbiosis had to be distinguished, and the interwoven causes made differentiation extremely difficult.

Treatment dilemma: Symptoms recurred after multi-line conventional therapy, and did not improve after probiotics and antibiotics were stopped. The patient had pancytopenia from cirrhosis and hypersplenism [WBC count 2.08×10⁹/L, PLT count 64×10⁹/L, hemoglobin (Hb) 94 g/L], with raised total bile acids (TBA), lowered total protein (TP) and albumin (ALB), and lowered ferritin (Fer) of 21 ng/mL, carrying a risk of nutritional imbalance and abnormal liver and kidney function. With relatively low immunity, treatment had to balance efficacy and safety, avoid adding to the liver and kidney burden or triggering infection, and was limited in the options available.

Complexity dilemma: The patient's multiple comorbidities interacted — cirrhosis impaired the intestinal mucosal barrier, while subtotal gastrectomy further disrupted digestion and absorption, together aggravating dysbiosis and forming a vicious cycle of "dysbiosis — intestinal barrier injury — worsening diarrhea". At the same time, pancytopenia increased the risk of treatment-related infection and bleeding, further raising the difficulty of treatment and the probability of complications.

II. Decision-Making: MDT Core Analysis and Strategy Deliberation

After multidisciplinary team assessment, the currently available options were:

1. Option A (intensified conventional drug therapy)

Theoretical basis: Based on the dual mechanisms of post-surgical malabsorption and dysbiosis, adjust the type and dose of probiotic preparations, combine digestive enzymes and intestinal mucosal protectants, and optimize the nutritional support plan.

Potential benefit: Simple to perform and highly safe; can improve digestive and absorptive function to some degree and help regulate the gut microbiota.

Risks and bottlenecks: The patient had already tried many probiotics and digestive enzymes with limited efficacy and fluctuating symptoms; further adjustment would most likely fail to fully correct the dysbiosis. Long-term medication might add to the liver's metabolic burden, conflicting with the treatment of his underlying cirrhosis.

2. Option B (repeat anti-infective therapy)

Theoretical basis: Speculating that there might be occult intestinal bacterial infection or small intestinal bacterial overgrowth.

Potential benefit: If an infectious factor were present, anti-infective therapy might control the diarrhea.

Risks and bottlenecks: Repeated stool routine examinations and bacterial and fungal cultures found no pathogens, so the indication for anti-infective therapy was unclear; blindly using antibiotics could further destroy the intestinal microbiota balance, aggravate mucosal barrier injury in a patient with cirrhosis, and increase the risk of resistance.

3. Option C (fecal microbiota transplantation)

Theoretical basis: Gut microbiota testing clearly indicated dysbiosis, and other core causes — tumor recurrence and infection — had been excluded, meeting the indications for fecal microbiota transplantation. This technique can directly replenish healthy gut microbiota, rebuild the microecological balance, address dysbiosis-related diarrhea at its root, and has relatively little impact on the liver's metabolic burden.

Potential benefit: It offered the prospect of thoroughly improving the diarrhea symptoms, breaking the vicious cycle of "dysbiosis — intestinal barrier injury — worsening diarrhea", and possibly indirectly improving nutrient absorption and general condition.

Risks and bottlenecks: With cirrhosis and pancytopenia, the patient had relatively low immunity, so the risk of post-transplant infection and adverse reactions was higher than in an ordinary patient. The timing of treatment had to be strictly controlled, avoiding the acute exacerbation phase of underlying disease; and the transplantation route and pretreatment regimen had to be individualized to balance efficacy and safety.

4. Option D (palliative symptomatic treatment)

Positioning: The choice if the patient could not tolerate fecal microbiota transplantation or if MDT assessment judged the transplant risk too high.

Pros and cons: It could only temporarily relieve symptoms through antidiarrheal drugs and nutritional support, without addressing the core cause; the patient's long-term quality of life would be poor, and diarrhea might further aggravate nutritional imbalance and the burden on liver and kidney function.

Final Decision and Implementation

The MDT team reached consensus, choosing Option C (fecal microbiota transplantation) and drawing up an individualized execution plan:

1. Consensus plan: First perform pretreatment (including nutritional support, supplementation of hematopoietic substrates and intestinal decontamination); once the patient's nutritional status improved and there was no evidence of infection, place a tube under colonoscopy and instill the bacterial suspension in stages, followed by probiotics after the procedure to maintain gut microbiota balance.

2. Decision drivers: The clear evidence of dysbiosis from gut microbiota testing; the persistent ineffectiveness of conventional therapy; the urgency of treatment demand due to multiple comorbidities; the evidence-based support for fecal microbiota transplantation; and its advantage of relatively low burden on the liver.

3. Risk contingency plan:

Before transplantation: Complete coagulation and liver function tests and assess hepatic reserve; improve hematopoietic function by supplementing vitamin B12, folic acid and polysaccharide iron complex; perform intestinal decontamination with oral rifaximin; screen for respiratory and intestinal pathogens to ensure no infection; and strictly screen the donor (including infectious diseases and gut microbiota testing).

During transplantation: Closely monitor vital signs, abdominal pain and bleeding; immediately stop the procedure if there are signs of severe discomfort or bleeding.

After transplantation: Closely monitor blood counts, liver function, coagulation and infection markers; prepare contingency plans for infection and bleeding; avoid hepatotoxic drugs, and avoid antibiotics unless necessary.

III. The Breakthrough: Treatment Course and Technical Points

1. Treatment Execution Map

Pretreatment (nutritional support + hematopoietic substrates + intestinal decontamination, 10 days) → donor screening and gut microbiota preparation (3 days) → tube placement under colonoscopy (day 13) → staged instillation of bacterial suspension (days 13-18, 6 consecutive days) → postoperative supportive care (probiotic supplementation + dietary adjustment + comorbidity management, 4 weeks) → efficacy assessment and follow-up.

2. In-Depth Analysis of Key Stages

(1) Pretreatment stage:

Nutritional and hematopoietic support: Compound vitamin B 1 tablet 3 times/day, folic acid tablets 5 mg once/day, and polysaccharide iron complex capsules 0.15 g once/day to supplement hematopoietic substrates; continued oral digestive enzymes and enteric-coated pancreatin tablets to improve digestion and absorption; whole-nutrient nutritional support, 1 bottle daily, to maintain energy supply.

Intestinal decontamination: Oral rifaximin 0.2 g 4 times/day for 3 consecutive days to reduce the load of harmful intestinal bacteria and create conditions for the transplanted microbiota to colonize.

Goal achieved: After pretreatment, the patient's nutritional status improved, there was no evidence of infection, blood counts across the three lines were more stable than before, and liver function and coagulation showed no obvious abnormality — meeting the conditions for transplantation.

(2) Transplantation procedure:

Tube placement under colonoscopy: After intravenous sedation and anesthesia, the colonoscope was inserted through the anus and a fecal microbiota transplantation tube was placed at the ileocecal region; after placement, an abdominal plain film confirmed the tube was in place and patent.

Staged instillation of bacterial suspension: The stool suspension was warmed to 37-38 °C and slowly instilled into the ileocecal region along the transplant tube, once daily for 6 consecutive days; each instillation was kept to more than 30 minutes to avoid intestinal spasm or abdominal pain from too rapid an infusion.

IV. Outcome Assessment and Follow-up Strategy

1. Short-Term Efficacy

One month after transplantation (December 2025), an efficacy assessment was performed:

Symptom improvement: The patient's diarrhea was clearly relieved compared with before treatment, the frequency of abdominal pain episodes decreased, and daily bowel movements fell from 5-10 before the procedure to 1-3. Morning bowel movements were mostly formed soft stool, with occasional diarrhea triggered by abdominal pain only after breakfast, being watery stool; overall symptom severity was markedly reduced.

Gut microbiota changes: A repeat gut microbiota test on December 14, 2025 showed that the originally markedly increased harmful bacteria of the gut-brain, gut-skin and gut-metabolism axes (such as Sutterella and Holdemanella) were clearly reduced, with no extremely abnormal elevations of any genus and no abnormal increase of Clostridium difficile. However, some harmful bacteria remained (the Gram-positive harmful Clostridioides and the Gram-negative harmful Fusobacterium and Neisseria), and beneficial bacteria (Faecalibacterium and Coprococcus) were still absent. The microbiota structure had improved markedly compared with before transplantation, but had not fully returned to normal.

General status: Blood counts across the three lines were more stable than before the procedure, liver function and nutritional markers showed no obvious abnormality, no serious transplantation-related adverse reactions occurred, and performance status remained good (ECOG score 0).

2. Survival and Functional Status

At the 2-month follow-up after transplantation, defecation remained stable at 1-3 times per day with no severe abdominal pain attacks, dietary tolerance continued to improve, and the patient could eat easily digestible soft food normally. Weight was maintained at around 57 kg, daily activities were unrestricted, and quality of life was clearly improved compared with before the procedure; however, occasional watery stool still occurred after breakfast.

3. Subsequent Treatment and Follow-up Plan

(1) Maintenance therapy: Continue oral high-activity compound probiotic preparations (dissolved in water below 37 °C before bedtime) to replenish the deficient beneficial genera; continue supplementing vitamin B12, folic acid and iron to improve hematopoietic function; and strictly follow the dietary management plan, avoiding raw and cold, spicy, gas-producing foods and gluten-containing products.

(2) Follow-up monitoring: Repeat gut microbiota testing at 1, 2, 6, 12 and 18 months after transplantation to dynamically assess microbiota recovery; recheck blood counts, liver function, coagulation and tumor markers (CEA, CA125 and others) every 3 months; and recheck abdominopelvic CT and gastroscopy every 6 months to monitor the underlying disease and tumor status.

(3) Lifestyle guidance:

Dietary management: Continue the principle of "gradual progression, small frequent meals", with daily water intake of 2000-2500 mL, gradually increasing the variety of vegetables, fruits and nuts, adding 1-2 new food items per day, and avoiding gastrointestinal intolerance.

Exercise management: Aerobic activity 4 times per week (40-60 minutes each) and resistance training twice per week (20-30 minutes each) to strengthen the physique and improve intestinal motility.

Other: Strictly avoid alcohol and the abuse of antibiotics, choosing anti-inflammatory patent Chinese medicines only when necessary; keep regular hours and avoid staying up late to reduce triggers of gut microbiota disturbance.

V. Insights from This Case

1. Insights on Diagnostic Thinking

(1) For refractory diarrhea combined with multiple comorbidities, a "multi-dimensional cause-screening system" should be established, breaking out of the limitation of a single-cause view and comprehensively considering surgical history, underlying diseases and gut microecology, supported by precise tests such as gut microbiota sequencing and PET-CT to clarify the core cause and avoid blind treatment.

(2) When conventional therapy fails, innovative techniques should be introduced promptly, but the pattern of treatment response in complex cases must be objectively recognized — dysbiosis caused by multiple comorbidities can rarely be fully corrected by a single treatment; after a partial response, the plan should be dynamically adjusted according to microbiota re-test results, avoiding the one-sided pursuit of a "one-time cure".

(3) The diagnosis and treatment of patients with multiple comorbidities require a mindset of "holistic assessment + long-term management", attending not only to the diarrhea symptom itself but also to control of underlying diseases, sustained improvement of nutritional status and dynamic monitoring of the gut microbiota, raising overall efficacy through multi-dimensional, long-cycle intervention.

2. Insights on the MDT Collaboration Model

(1) The key to this case's success lay in the MDT team's "full-process, multi-dimensional collaboration": multidisciplinary joint assessment of the cause and an individualized pretreatment plan before the procedure, coordinated completion of the transplantation during the procedure, and joint monitoring of adverse reactions, changes in underlying disease and microbiota recovery afterward — forming a closed-loop chain of "diagnosis — intervention — assessment — adjustment" that effectively avoided the limitations of single-discipline decision-making.

(2) For patients with complex underlying diseases, MDT collaboration must emphasize "risk anticipation and dynamic adjustment": given the patient's cirrhosis and pancytopenia, the hepatology and critical care departments intervened early to assess risk; when an upper respiratory tract infection occurred, the timing of transplantation was adjusted promptly; and when a partial response appeared, a second assessment was quickly launched and an optimized plan drawn up — reflecting the flexibility and continuity of MDT collaboration.

(3) Establish a synergy mechanism of "underlying disease — specialty treatment — microecological regulation": in this case, deep collaboration among the gastrointestinal tumor centre, the hepatology department and the intestinal microecology therapy centre integrated post-gastrectomy management, cirrhosis treatment and fecal microbiota transplantation, offering a reproducible collaboration model for the staged treatment of similar patients with multiple comorbidities.

3. Insights on Technology Application

(1) The use of fecal microbiota transplantation in refractory diarrhea with multiple comorbidities must follow the principle of "individualized design + dynamic assessment": pretreatment drugs must avoid hepatotoxicity, the transplantation route must balance efficacy and safety, and the maintenance plan must be adjusted according to microbiota re-test results — the standardized protocol for ordinary patients cannot simply be applied.

(2) A single fecal microbiota transplantation may achieve only a "partial response"; for complex cases with cirrhosis and post-surgical malabsorption, a stepwise plan of "multi-cycle treatment + targeted supplementation" is needed, and the persistent absence of beneficial bacteria suggests that specific probiotics should be supplemented after the procedure to consolidate the transplant's efficacy.

(3) Potential pitfalls to remember: for patients with cirrhosis and hypersplenism, the timing of transplantation must be strictly controlled to avoid performing it during infection or acute exacerbation of underlying disease; antibiotics must not be abused after the procedure lest they disrupt the not-yet-stable post-transplant microbiota balance; and after a partial response, the microbiota should be re-tested promptly to clarify residual problems and avoid blindly repeating treatment.

4. Unresolved Questions and Outlook

(1) Although this patient achieved an improved microbiota structure and symptom relief after a single fecal microbiota transplantation, the reason for the persistent absence of beneficial bacteria still needs to be explored — it may be related to sustained damage to the intestinal mucosal barrier from cirrhosis and an abnormal post-surgical digestive environment — and requires long-term follow-up and further investigation.

(2) For this special population with post-gastrectomy status and cirrhosis, the mechanisms by which dysbiosis and underlying disease interact are not yet fully clear; future basic and clinical research is needed to provide a theoretical basis for more targeted diagnostic and treatment plans.

Expert Commentary

Prof. Ma Zhiqiang

President of Beijing Arion Cancer Hospital; Associate Chief Physician; Professor.

This patient presented with chronic diarrhea lasting more than four years that, despite the use of antibiotics, supplementation with a variety of probiotics and digestive enzymes, and treatment with traditional Chinese medicine, could never be resolved — and his wish to find an answer was very strong. The team carried out detailed examinations and assessments, understanding that the patient was post-gastrectomy for gastric cancer (4 years without recurrence) and had cirrhosis, splenomegaly and hypersplenism leading to pancytopenia. These complex underlying diseases were both the cause of the gut microbiota imbalance and an important factor making it difficult to improve.

In handling this difficult and complex situation, the diagnostic and treatment team deserves praise and recognition for the following points:

1. Careful, comprehensive and detailed examination, especially determination of the gut microbiota profile, which provided evidence-based support for further analysis of the condition and for treatment decisions;

2. The full-course implementation of MDT, which provided an institutional safeguard for comprehensively grasping the patient's condition;

3. At the decision-making level, multiple options were offered to the patient, and — most valuably — the advantages and disadvantages of each scheme were explained in a scientific and reasonable way;

4. Helping the patient make the most reasonable choice — fecal microbiota transplantation treatment.

Sufficient, meticulous and thoughtful preparation was made during the peri-treatment period, and after treatment the efficacy and the improvement of the bacterial spectrum were fully assessed. In summary, the review of this case's diagnosis and treatment also provides good experience for the diagnosis and treatment of similar patients in the future.