Idiopathic mesenteric phlebosclerosis associated with long-term herbal medicine use: A case report

Abstract

BACKGROUND

Idiopathic mesenteric phlebosclerosis (IMP) is a rare chronic ischemic colonic disease associated with mesenteric venous sclerosis and calcification, often linked to long-term use of herbal medicines containing gardenia.

CASE SUMMARY

A man in his late 50s presented with a 1-month history of severe diarrhea, right-sided abdominal pain, and weight loss. He had a 20-year history of intermittent herbal medicine use. Laboratory tests showed elevated inflammatory markers. Colonoscopy revealed bluish-purple mucosa with luminal narrowing. Computed tomography demonstrated diffuse colonic wall thickening and characteristic linear calcifications along the mesenteric veins. Histopathology revealed tubular adenoma-like changes without definite malignancy. The patient improved following conservative treatment including discontinuation of herbal medicine.

CONCLUSION

IMP should be considered in patients with chronic gastrointestinal symptoms and a history of long-term herbal medicine use. Recognition of characteristic imaging findings is essential, and careful long-term surveillance is recommended when adenoma-like changes are present.

Key Words: Idiopathic mesenteric phlebosclerosis; Mesenteric venous calcification; Herbal medicine; Colonoscopy; Case report

Core Tip: Idiopathic mesenteric phlebosclerosis should be considered in patients presenting with chronic gastrointestinal symptoms and a history of long-term gardenia-containing herbal medicine use. Characteristic linear mesenteric venous calcifications on computed tomography are the key diagnostic clue. Adenoma-like histological changes may occur but their malignant potential remains uncertain. Conservative management with discontinuation of implicated herbal medicine can achieve favorable outcomes in patients without severe complications. Long-term surveillance is recommended when adenoma-like changes are present.

INTRODUCTION

Idiopathic mesenteric phlebosclerosis (IMP), a rare form of ischemic colitis, predominantly affects the mesenteric veins and colon. IMP was first reported by Koyama et al[1] in 1991. It occurs predominantly in East Asian populations and has been associated with prolonged use of traditional herbal medicines, particularly preparations containing gardenia[1,2]. The pathological process may lead to chronic venous obstruction, impaired colonic perfusion, ischemic mucosal injury, fibrosis, and, in severe cases, intestinal obstruction, necrosis, or perforation[3]. IMP’s presentation can vary, with symptoms such as abdominal pain, diarrhea, and bloating. This report aims to emphasize the diagnostic value of characteristic computed tomography (CT) findings, the importance of identifying long-term herbal medicine exposure, and the need for cautious interpretation of adenoma-like histological changes in IMP.

CASE PRESENTATION

Chief complaints

Persistent diarrhea, right-sided abdominal pain, and weight loss for 1 month.

History of present illness

A man in his late 50s was admitted to our hospital with the above complaints. He developed watery diarrhea approximately 1 month before admission, with stool frequency gradually increasing from 3-4 times per day to more than 10 times per day. The diarrhea was accompanied by intermittent right-sided abdominal pain, abdominal distension, and progressive weight loss (approximately 5 kg over 1 month). There was no visible blood in the stool, no fever, and no nausea or vomiting at onset. The patient initially self-medicated with antidiarrheal agents without improvement. As symptoms progressively worsened, he presented to our hospital for further evaluation.

History of past illness

The patient had a history of ankylosing spondylitis for more than 30 years. He had intermittently taken traditional herbal medicine containing gardenia (including Danzhi Xiaoyao San and Huanglian Jiedu Tang) for approximately 20 years. He was diagnosed with chronic hepatitis B infection 1 month before admission and had not received antiviral therapy before hospitalization. No history of diabetes mellitus, hypertension, cardiovascular disease, or previous abdominal surgery was reported.

Personal and family history

The patient denied a history of smoking or alcohol use. There was no family history of inflammatory bowel disease, colorectal cancer, or mesenteric vascular disease. No family members had a history of long-term herbal medicine use.

Physical examination

On admission, the patient appeared chronically ill with mild malnutrition. Vital signs were stable: Body temperature 36.8 °C, heart rate 82 beats/minute, blood pressure 125/78 mmHg, respiratory rate 18 breaths/minute. Abdominal examination revealed mild distension, tenderness in the right lower quadrant without rebound tenderness or guarding, and hyperactive bowel sounds. No palpable abdominal mass was noted.

Laboratory examinations

Laboratory testing showed leukocytosis and elevated inflammatory markers, including C-reactive protein of 151.73 mg/L and interleukin-6 of 117.30 pg/mL. Hepatitis B serology was consistent with chronic hepatitis B infection. Fecal occult blood testing was positive, and stool culture identified Candida albicans, which was interpreted cautiously as possible colonization rather than evidence of causative infection.

Imaging examinations

Endoscopic findings: Colonoscopy revealed nodular swelling, bluish-purple mucosa, mucosal friability, and luminal narrowing at the descending-sigmoid junction, which prevented further advancement of the endoscope (Figure 1A).

Figure 1 Endoscopic and histopathological findings. A: Colonoscopy showing nodular swelling, bluish-purple mucosa, mucosal friability, and luminal narrowing; B: Histopathological examination showing tubular adenoma-like epithelial changes without definite evidence of invasive malignancy.

Histopathology: Biopsy showed tubular adenoma-like epithelial changes without definite evidence of invasive malignancy (Figure 1B).

Imaging findings: Abdominal CT demonstrated diffuse colonic wall thickening and extensive linear calcifications along the mesenteric veins and colonic wall, findings highly suggestive of IMP (Figure 2).

Figure 2 Abdominal computed tomography findings. Abdominal computed tomography showing diffuse colonic wall thickening and extensive linear calcifications along the mesenteric veins and colonic wall, findings characteristic of idiopathic mesenteric phlebosclerosis.

MULTIDISCIPLINARY EXPERT CONSULTATION

Not applicable. The diagnosis was established based on characteristic imaging and endoscopic findings in the context of long-term herbal medicine exposure. Treatment decisions were made by the attending gastroenterology team.

FINAL DIAGNOSIS

IMP.

TREATMENT

After the diagnosis of IMP was established, the patient received conservative management. The treatment included: (1) Immediate and permanent discontinuation of all gardenia-containing herbal medicines; (2) Oral montmorillonite powder for symptomatic control of diarrhea; (3) Intravenous fluid replacement and electrolyte correction; (4) Probiotics to restore intestinal microbiota balance; (5) Levofloxacin for empirical anti-infective therapy; and (6) Tenofovir alafenamide for chronic hepatitis B antiviral treatment. Surgical intervention was not indicated as the patient had no evidence of perforation, necrosis, complete intestinal obstruction, or uncontrolled gastrointestinal bleeding.

OUTCOME AND FOLLOW-UP

Following 15 days of conservative treatment, the patient’s symptoms improved significantly. Diarrhea frequency decreased from more than 10 episodes per day to 1-3 episodes per day, and stool consistency improved. Abdominal pain and distension resolved. The patient was discharged in stable condition. At 3-month follow-up, the patient remained clinically stable without recurrence of severe diarrhea or abdominal pain. He reported no resumption of herbal medicine use. Given the presence of tubular adenoma-like histological changes and the technical difficulty of repeated colonoscopy due to luminal narrowing, long-term surveillance was recommended. The follow-up plan includes periodic abdominal CT to monitor disease progression and consideration of non-invasive biomarker-based monitoring strategies.

DISCUSSION

A literature search was performed in PubMed, Ovid, China National Knowledge Infrastructure, and Wanfang Data from database inception to January 2026 using the terms ‘idiopathic mesenteric phlebosclerosis’, ‘mesenteric phlebosclerosis’, and ‘phlebosclerotic colitis’. Case reports and case series with sufficient individual clinical information and radiological or pathological evidence supporting the diagnosis of IMP were included. Review articles without individual patient data, duplicate reports, and articles lacking sufficient diagnostic information were excluded. When duplicate cases were identified, the most complete and recent report was retained. Data on demographics, clinical presentation, herbal medicine exposure, management, and outcomes were extracted and summarized. Thirty-four publications involving 96 patients were identified (Table 1). The majority were male (59.4%), with a mean age of 63.6 years. Abdominal pain was the most common symptom (55.2%). Long-term herbal medicine exposure was reported in 65.6% of cases. Conservative management was reported in 73 patients (76.0%), whereas surgical resection was required in 16 patients (16.7%), representing a clinically meaningful proportion. Overall mortality was 5.2%.

Table 1 Clinical characteristics and management of reported cases of idiopathic mesenteric phlebosclerosis (n = 96).

Variable	n (%)
Sex
Male	57 (59.4)
Female	39 (40.6)
Mean age (range)	63.6 (22-88)
Clinical manifestations
Abdominal pain	53 (55.2)
Abdominal distension	22 (22.9)
Diarrhea	12 (12.5)
Vomiting	11 (11.5)
Gastrointestinal bleeding/melena	7 (7.3)
Fever	7 (7.3)
Intestinal obstruction	4 (4.2)
Asymptomatic	14 (14.6)
Risk factors
Long-term herbal medicine use	63 (65.6)
No documented herbal exposure	28 (29.2)
Not reported	5 (5.2)
Management
Conservative treatment	73 (76.0)
Surgical resection	16 (16.7)
Not reported	7 (7.3)
Mortality	5 (5.2)

Etiology and pathogenesis

IMP is a rare chronic ischemic colonic disease, and its pathogenesis remains incompletely understood. The disease has been most consistently associated with long-term use of herbal medicines, whereas the role of autoimmune conditions remains uncertain. The majority of reported cases (65.6%) have a history of long-term use of herbal medicines, particularly those containing gardenia (geniposide), such as Danzhi Xiaoyao San and Huanglian Jiedu Tang. The suspected pathophysiology is that geniposide is metabolized by colonic bacteria into genipin, which interacts with proteins in the mesenteric venous blood, leading to submucosal collagen accumulation[3,4]. This eventually causes venous endothelial proliferation, fibrosis, and vascular obstruction. Some studies have reported coexistence of IMP with autoimmune diseases; however, whether these conditions contribute directly to IMP pathogenesis remains unclear[5]. In the present case, the patient had ankylosing spondylitis; however, the available evidence is insufficient to determine whether it contributed to the development of IMP. Chronic hepatitis B was also present, but its relationship with IMP remains unclear and should not be interpreted as causal. Further research is needed to clarify the potential interaction between chronic liver diseases and IMP. The isolation of Candida albicans from stool culture should be interpreted with caution. Although IMP is an ischemic rather than infectious condition, stool detection of Candida albicans may reflect intestinal colonization or microbiota disturbance rather than invasive fungal infection. In addition, the chronic ischemia and tissue damage specific to IMP can disrupt the normal barrier function of the intestines, which may create an environment conducive to opportunistic fungal infections. Therefore, a causal relationship between Candida albicans and the patient’s diarrhea cannot be established based on stool culture alone.

Diagnosis

The clinical manifestations of IMP are non-specific, making early diagnosis challenging. Mild disease may present with chronic abdominal pain and diarrhea, whereas severe disease may progress to intestinal obstruction, necrosis, or perforation requiring urgent surgical intervention[6,7]. In this case, the patient presented with gastrointestinal symptoms compatible with IMP, together with a long history of gardenia-containing herbal medicine use. However, IMP may have an insidious onset, and some patients remain asymptomatic, which can delay diagnosis. Laboratory findings in IMP are non-specific, and in the above case, the laboratory findings were positive for fecal occult blood, electrolyte imbalance, and increased levels of inflammatory markers, such as C-reactive protein and interleukin-6, which may be due to chronic diarrhea and ulceration of the mucosa. CT imaging plays a central role in the diagnosis of IMP because mesenteric venous calcification is a characteristic finding[8,9]. Typical findings include diffuse colon wall thickening and mesenteric vein calcifications, particularly in the right colon[10,11]. In this case, the abdominal CT scan showed marked thickening of the colon wall with diffuse calcification, indicating IMP[12,13]. Colonoscopy typically shows a dark purple or blackish mucosa, indicating submucosal fibrosis and ischemia[14]. Additionally, the colon wall may appear rigid, and luminal narrowing with ulcers or strictures can be present. Pathological examination may reveal adenoma-like epithelial changes; however, the malignant potential of such changes in the setting of IMP remains uncertain[15]. In the present case, these histological findings support the need for careful follow-up, but they should not be interpreted as definite evidence of malignant transformation[15,16].

Treatment and prognosis

Currently, there are no disease-specific pharmacological therapy for IMP, and management is individualized according to symptom severity and complications. Discontinuation of potentially implicated herbal medicine is critical, as continued exposure may contribute to disease progression[17,18]. As demonstrated in this case, symptomatic support (such as antidiarrheals, fluid replacement, and probiotics) and cessation of herbal medicines led to significant clinical improvement. Conservative management may result in clinical remission in patients without complications such as obstruction, perforation, necrosis, or uncontrolled bleeding[4,19]. In more severe cases, such as those with bowel perforation, necrosis, or obstruction, surgical resection is required. Our literature review showed that 73 of 96 patients (76.0%) received conservative treatment, whereas 16 patients (16.7%) underwent surgical resection, usually because of complications or severe disease manifestations. Compared with patients requiring surgery, the present patient had no evidence of perforation, necrosis, complete obstruction, or uncontrolled gastrointestinal bleeding, which supported an initial conservative approach. The prognosis of IMP is generally favorable when the disease is recognized early and implicated herbal medicine is discontinued; however, severe complications can occur and may require surgery[13,20,21]. Given the presence of tubular adenoma-like changes and the technical challenges associated with repeated colonoscopy in patients with luminal narrowing and friable mucosa, non-invasive surveillance strategies may be of clinical value. Recent advances in liquid biopsy, including circulating cfDNA methylation markers such as miR-129-2 promoter methylation, have shown promising diagnostic performance for detecting advanced adenomas and early-stage colorectal cancer[22]. Although such biomarkers have not been specifically validated in IMP, they may represent potential adjunctive tools for long-term surveillance in selected patients.

Clinical implications

Many patients may respond to conservative management after discontinuation of potentially implicated herbal preparations, particularly in the absence of severe complications. Surgical intervention should be considered in patients with complications such as obstruction, perforation, necrosis, uncontrolled bleeding, or failure of conservative therapy. Early diagnosis is clinically important because timely recognition and withdrawal of implicated herbal exposure may slow disease progression and reduce the need for invasive intervention[23].

CONCLUSION

IMP is an uncommon but important cause of chronic ischemic colitis, particularly in patients with long-term exposure to gardenia-containing herbal medicine. Characteristic mesenteric venous calcifications on CT are key to diagnosis. Discontinuation of implicated herbal products and individualized conservative management may lead to favorable outcomes in selected patients. Increased awareness of this condition may improve early recognition, guide appropriate treatment selection, and support long-term surveillance when adenoma-like histological changes are present.